A car traveling at a constant speed goes a distance of 3600m in 120 s. What is the car's speed?
a. 30m/s
b. 120m/s
c. 4320 m/s
d. 435000m/s
a. 30 m/s
When something falls to the ground, it accelerates. This acceleration is called the acceleratio due to graity and is symbolized by the letter g. What is the value of g on Earth's surface?
a. om/s^2
b. about 5m/s^2
c. about 10m/s^2
d. about 20m/s^2
e. abou
c. about 10 m/s^2
Heather rides a bycicle 900 m, turns around to face the opposite direction, and rides 1,200 m. What is her total velocity if she rides for 60 s?
a. 5m/s
b. 15m/s
c. 20m/s
d. 35 m/s
d. 35 m/s
If the freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by:
a. 5m/s
b. 10m/s
c. 15m/s
d. a variable amound
e. a rate depends on its initial speed
b. about 10m/s
Modern atomic theory began around 1800 and has gradually changed as new experimental results became available. Which of these describes how new experimental results will MOST often affect existing atomic theory?
a. the existing theory will be replaced by
d. the existing theory will be revised and extended to include new results
Henry Becquerel discovered nuclear radiation while working with phosphorescent materials .These materials, after exposure to sunlight would emit radiation that made an image on photographic film. When he found a material that made an image on filem even w
b. stating a hypothesis to explain unexpected observations
in the absence of air resistance, objects fall at constant:
a. speed
b. velocity
c. acceleration
d. distances each successive second
e. all of the above
c. acceleration
It is said that when Newton saw an apple fall from a tree, it occurred to him that the gravitational force that caused the apple to fall could be the same force that determines the path of the Moon in its orbit aroudn the Earth. His calculatons showed tha
a. validation a theory by using it to explain events
speed is:
a. measure of how fast somethign is moving
b. always measured in terms of a unit of distance divided by a unit of time
c. the distance covered per unit time
d. all of the above
e. none of the above
d. all of the above
A car accelerates at 2m/s^2. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 20m/s?
a. 2 seconds
b. 10 seconds
c. 20 seconds
d. 40 seconds
e. none of the above
b. 10 seconds
You throw a golf ball downward from a roof of a building at a speed of 12m/s. How fast is the ball going after 5 seconds?
a. 0m/s
b. 38m/s
c. 62 m/s
d. 50 m/s
c. 62m/s
You shoot an arrowupwards at a speed of 80m/s. How long will it take for that arrow to reach its highest point?
a. 8 sec
b. 800 sec
c. 0.125 sec
d. none of the above
a. 8 sec
A car travels at a constant speed of 40 m/s. If it travels for 3 s, how far did it travel?
a. 13.3 m
b. 120 m
c. 0.075 m
d. 600 m
b .120 m
_______ is a quantity divided by time.
a. velocity
b. speed
c. acceleration
d. rate
d. rate
Speed is...
a measure of how fast something is moving
always measured in terms of a unit of distance divided by a unit of time
the distance covered per unit of time
One possible unit of speed is
miles per hour
light years per century
kilometer per hour
When you look at the speedometer in a moving car, you can see the car's...
instantaneous speed
Acceleration is defined as the CHANGE in
velocity divided by the time interval
Suppose you are in a car that is going around a curve. The speedometer reads a constant 30 miles per hour. Which of the following is NOT true?
your velocity is constant
A train travels 6 meters in the first second of travel, 6 meters again during the second second of travel, and 6 meters again during the third second. Its acceleration is
0m/s2
In the absence of air resistance, object fall at constant...
acceleration
A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of the ball when caught would be...
the same as the speed it had when thrown upwards
Suppose an object is in free fall. Each second the object falls...
the same distance as in the second before
Consider drops of water leaking from a water faucet. As the drops fall, they...
remain at a relatively fixed distance from each other
Suppose you take a trip that covers 180 km and takes 3 hours to make. Your average speed is
60 km/h
Suppose a car is moving in a straight line and steadily increases its speed. It moves from 35 km/h to 40 km/h the first second and from 40 km/h to 45 km/h the next second. What is the car's acceleration?
5 km/h.s
A ball is thrown straight up. At the top of its path, its instantaneous speed is
0m/s
A ball is thrown straight up. At the top of its path, its acceleration is
10m/s2
When something falls to the ground, it accelerates. This acceleration is called the acceleration due to gravity and is symbolized by the letter g. what is the value of g on Earth's surface?
About 10 m/s^2
A car accelerates at 2m/s^2. assuming the car starts from rest, how much time does it need to accelerate to a speed of 20 m/s?
10 seconds
If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by
About 10 m/s
If a ball were equipped with a speedometer and allowed to freely fall on a planet where the acceleration due to gravity is 23 m/s^2, the reading on the speedometer would increase each second by
A rate that depends on its initial speed
if a projectile is fired straight up at a speed of 10 m/s , the total time to return to its starting point is about
2 seconds
a pencil lays on your desk. If the earth is moving around the sun at a speed of 30 km/s, how fast is the pencil moving relative to the desk? How fast is the pencil moving relative to the sun?
0 km/s; 30 km/s
Friction is a force that always acts..
Opposite to an objects motion
The law of inertia states that an object
will continue moving at the same velocity unless an outside force acts on it
will continue moving in a straight line unless an outside force acts on it
that is not moving will never move unless a force acts on it
at rest will remain at rest unless acted on by an outside force
After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals
zero, since no force is necessary to keep it moving
If the force of gravity suddenly stopped acting on the planets, they would
move in a straight line tangent to their orbits
Friction
comes from microscopic bumps that act as obstructions to the object's motion
is the name given to the force acting between surfaces sliding past one another
acts in a direction that opposes the motion of an object
One object has twice as much mass as another object. The first object also has twice as much
inertia
Compared to its mass on Earth, the mass of a 10-kg object on the moon is
the same
You would have the largest mass of gold if your chunk of gold weighed 1 N on
the moon
A bag of sports equipment has a mass of 10.0 kg and a weight of
9.8 N
Which of the following is NOT true about Aristotle's concept of violent motion?
Violent motion is thought to be either straight up or straight down
You and a friend are jumping on a trampoline. Why does Earth, which is rapidly orbiting around the sun, not move under your feet when you jump?
Newton's first law holds that your body moves along with Earth because it is not compelled to change its motion by an unbalanced force
the rate at which distance is covered is called speed
True
average speed is defined as the time it takes for a trip divided by the distance
False
velocity is different from speed in that velocity is speed in a given direction
True
Unit of velocity is the meter
False
the rate at which velocity changes with time is called acceleration
True
a unit of acceleration is meters per second
False
when a car rounds a corner at a constant speed, its acceleration is zero
False
even though a car is slowing down, it is still accelerating, in the most general definition of acceleration
True
a ball is thrown into the air. at the highest point, the ball has zero velocity and zero acceleration
False
as a ball falls freely, the distance it falls each second it the same
False
when we discuss the motion of something, its motion is described relative to something else
True
unless stated otherwise, when we discuss the speeds of things, we mean with respect to the center of the universe
False
friction refers to the force between two surfaces that are sliding past each other
True
if a hockey puck were to slide on a perfectly frictionless surface, it will eventually slow down because of its inertia
False
if you were to slide a hockey puck across a frictionless ice rink, there must be a horizontal force on it to keep it in motion
False
the amount of matter in an object is its weight
False
the SI unit of mass is the newton
False
an astronaut weighs the same on Earth as in space
False
an astronaut has the same mass on Earth as in space
True
in the fourth century B.C., Aristotle divided motion into 2 types: natural motion and violent motion
True
If you drop a feather and a coin at the same time in a vacuum tube, which will reach the bottom first?
A.The coin
B.The feather
C.Neither-they will reach the bottom at the same time
c
Acceleration is defined as the CHANGE in____.
A.Distance divided by the time interval.
B.Velocity divided by the time interval.
C.Time it takes to move from one speed to another speed.
D.Time it takes to move from one place to another place.
E.Position of
b
Ten seconds after starting from rest, a freely falling object will have a speed of about_____.
A.10 m/s
B.50 m/s
C.100 m/s
D.500 m/s
E.more than 500 m/s
c
Speed is______.
A.a measure of how fast something is moving.
B.the distance covered per unit time.
C.always measured in terms of a unit of distance by a unit of time.
D.all of the above.
E.none of the above
d
When you look at the speedometer in a moving car, you can see the car's_____.
A.instantaneous speed
B.average speed
C.instantaneous acceleration
D.average acceleration
E.average distance traveled
a
Suppose an object is in free fall. Each second the object falls_____.
A.with the same average speed
B.with the same instantaneous speed
C.the same distance as in the second before
D.a larger distance than in the second before
E.none of the above
d
In the absence of air resistance, objects fall at constant______.
A.velocity
B.speed
C.acceleration
D.distances each successive second
E.all of the above
c
A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of the ball when caught would be______.
A.more than the speed it had when thrown upwards.
B.less than the speed it had when thrown upwards.
C.the same
c
A ball tossed vertically upwards rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always_____.
A.in the direction of motion
B.opposite its velocity
C.directed upward
D.directed d
d
A ball id thrown straight up. At the top of its path its acceleration is______.
A.0 m/s^2.
B.about 5 m/s^2.
C.about 10 m/s^2.
D.about 20 m/s^2.
E.about 50 m/s^2.
c
Consider drops of water leaking from a water faucet. As the drops fall they________.
A.get closer together
B.get farther apart
C.remain at a relatively fixed distance from each other.
b
A ball is thrown straight up. At the top of its path its instantaneous speed is______.
A.0 m/s^2.
B.about 5 m/s^2.
C.about 10 m/s^2.
D.about 20 m/s^2.
E.about 50 m/s^2.
a
Physics is the most basic science because______.
A.it is about the nature of basic things like fores, energy, and motion.
B.you can better understand science in general if you understand physics.
C.the ideas of physics extend into more complex sciences.
D
e
If you drop a feather and a coin at the same time in a tube filled with air, which will reach the bottom of the tube first?
A.The coin
B.The feather
C.Neither-they will reach the bottom at the same time
a
Dr.Hewitt stated in the video that what invention changed the way people lived and the very nature and structure of cities______.
A.elevator
B.mass transportation
C.roads
D.irrigation
E.concrete
a
If the force of gravity suddenly stopped acting on the planets, they would
A) continue to orbit the sun.
B) fly straight away from the sun.
C) move in a straight line tangent to their orbit.
D) spiral slowly away from the sun.
E) spiral slowly towards the
move in a straight line tangent to their orbit.
One object has twice as much mass as another object. The first object also has twice as much
A) inertia.
B) velocity.
C) gravitational acceleration.
D) energy.
E) all of the above
inertia.
You would have the largest mass of gold if your chunk of gold weighed 1 N (W = mg) on the
A) Moon (g = 1.62 m/s2)
B) Earth (g = 9.81 m/s2)
C) Jupiter (g = 25.95 m/s2)
D) Mars (g = 3.77 m/s2)
A) Moon (g = 1.62 m/s2)
A 100.00 N lantern is suspended by a rope . The tension in the rope is
A) 100.0 N.
B) 100 N.
C) 100. N
D) 100.00 N
D) 100.00 N
An apple weighs 1 N. The net force on the apple when it is in free fall is (Assume no air resistance)
A) 0 N.
B) 0.1 N.
C) 1 N.
D) 9.8 N.
E) none of the above
C) 1 N.
A car has a mass of 1000. kg and accelerates at 2.000 meters per second per second. What is the magnitude of the force acting on the car?
A) 500.0 N.
B) 1000. N.
C) 1500. N.
D) 2000. N.
D) 2000. N.
A tow truck exerts a force of 3000. N on a car, accelerating it at 2.000 m/s2. What is the mass of the car?
A) 500.0 kg
B) 1000. kg
C) 1500. kg
D) 3000. kg
C) 1500. kg
A block is dragged without acceleration in a straight-line path across a level surface by a force of 6 N. What is the frictional force between the block and the surface?
A) Less than 6 N
B) More than 6 N
C) 6 N
D) Need more information to say.
C) 6 N
Suppose a particle is accelerated through space by a constant 10-N force. Suddenly the particle encounters a second force of 10-N in a direction opposite to that of the first force. The particle
A) begins to decelerate and stop
B) continues to accelerate
C) continues at the speed it had when it encountered the second force.
. If you pull horizontally on a crate with a force of 150 N and the crate doesn't move, the friction force must be 150 N. Now if you pull with 250 N so the crate slides at constant velocity, the static friction force is
A) more than 150 N but less than 25
C) more than 250 N.
. You pull horizontally on a 50-kg crate with a force of 500 N, and the friction force on the crate is 250 N. The acceleration of the crate is
A) zero.
B) 2 m/s2.
C) 4 m/s2.
D) 5 m/s2.
D) 5 m/s2.
A speeding truck slams on its brakes and skids to a stop. If the truck's total mass were doubled, its skidding distance would be
A) half as far.
B) nearly as far, but not quite.
C) twice as far.
D) four times as far.
E) the same.
C) twice as far.
An unfortunate bug splatters against the windshield of a moving car. Compared to the deceleration of the car, the deceleration of the bug is
A) larger.
B) smaller.
C) the same.
A) larger.
14. Which of the following system of forces provides the block the highest net force?
a. 11 N 71 N
c. 227 N 153 N
b. 405 N 403 N
d. 22.7 N 15.3 N
c. 227 N 153 N
. According to Newton's third law, if you push gently on something, it will push
A) gently on you.
B) gently on something else.
C) on something only under the right conditions.
D) on you only if you aren't moving.
A) gently on you.
As an object falls freely in a vacuum, its
A) acceleration increases.
B) velocity increases.
C) both a and b
D) none of the above
B) velocity increases.
. A ball is thrown straight up. At the top of its path its instantaneous speed is
A) 0 m/s.
B) about 5 m/s.
C) about 10 m/s.
D) about 20 m/s.
E) about 50 m/s.
A) 0 m/s.
. A ball is thrown straight up. At the top of its path its acceleration is
A) 0 m/s/s.
B) about 5 m/s/s.
C) about 10 m/s/s.
D) about 20 m/s/s.
E) about 50 m/s/s.
C) about 10 m/s/s.
A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of the ball when caught would be
A) more than the speed it had when thrown upwards.
B) less than the speed it had when thrown upwards.
C) the same as
C) the same as the speed it had when thrown upwards.
5. Human reaction time is usually about 0.20 s. If your lab partner holds a ruler between your finger and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it? (Disregard air resistance. g = 9.81 m/s2.)
A) at
D) at least 19.6 cm
6. One-half second after starting from rest, a freely falling object will have a speed of about
A) 2.5 m/s.
B) 5 m/s.
C) 10 m/s.
D) 20 m/s.
E) none of the above
B) 5 m/s.
. If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by
A) about 15 m/s.
B) about 10 m/s.
C) about 5 m/s.
D) a variable amount.
E) a rate that depends on its initial speed.
B) about 10 m/s.
. Suppose a jumper claims a hang time of 2 seconds. Then that jumper must be able to jump a vertical distance of about
A) 1 m.
B) 2 m.
C) 3 m.
D) 4 m.
E) 5 m.
E) 5 m.
If you drop a feather and a coin at the same time in a vacuum tube, which will reach the bottom of the tube first?
A) The coin
B) The feather
C) Neither�they will both reach the bottom at the same time.
C) Neither�they will both reach the bottom at the same time.
10. If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting point is about
A) 1 second.
B) 2 seconds.
C) 10 seconds.
D) 20 seconds.
E) not enough information to estimate.
B) 2 seconds.
A car is moving with a uniform speed of 15.0 m/s along a straight path. What is the distance covered by the car in 12.0 minutes?
A. 1.02 x 10-3 km C. 8.00 x 10-5 km
B. 1.80 x 10-1 km D. 1.08 x 101 km
D. 1.08 x 101 km
What is the correct answer for the following problem? 5.300 / 3.1 =
A. 1.7 B. 1.71 C. 1.710 D. 1.7097 E. 2
A. 1.7
A man starts his car from rest and accelerates at 1 m/s2 for 2 seconds. He then continues at a constant velocity for 10 seconds until he sees a tree blocking the road and applies brakes. The car, decelerating at 1 m/s2, finally comes to rest. Which of the
/---\
A vector is a quantity that has
A. magnitude and time
B. magnitude and direction
C. time and direction
D. magnitude only
B. magnitude and direction
In the absence of air resistance, the angle at which a thrown ball will go the farthest is
A. 75 degrees
B. 60 degrees
C. 45 degrees
D. 30 degrees
E. 15 degrees
C. 45 degrees
A bullet fired horizontally hits the ground in 0.5 seconds. If it had been fired with a much higher speed in the same direction, it would have hit the ground (neglecting the earth's curvature and air resistance) in
A. less than 0.5 s
B. more than 0.5 s
C.
C. 0.5 s
At what part of a path does a projectile have minimum velocity?
A. When it is thrown.
B. Half-way to the top.
C. At the top of its path.
D. When it returns to the ground.
C. At the top of its path.
A ball is hurled into the air at an angle of 30 degrees and lands on a target that is at the same level as that where the ball started. The ball will also land on the target if it is thrown at an angle of
A. 40 degrees
B. 45 degrees
C. 55 degrees
D. 60 de
D. 60 degrees
The horizontal component of a projectile's velocity is independent of
A. the vertical component of its velocity
B. the range of the projectile
C. time
D. none of the above
A. the vertical component of its velocity
What is the resultant vector for the components Vx = 4.0, Vy = 7.0?
A. VR = 11, ? = 30�
B. VR = 8.1, ? = 30�
C. VR = 3.0, ? = 30�
D. VR = 11, ? = 60�
E. VR = 8.1, ? = 60�
E. VR = 8.1, ? = 60�
A cannonball is fired at some angle into the air. In the first second it moves 10.0 meters horizontally. Assuming it doesn't hit the ground, how far does it move horizontally in the next second?
A. More than 10.0 m
B. 10.0 m
C. Less than 10.0 m
D. There's
B. 10.0 m
A ball is thrown into the air at some angle. At the very top of the ball's path, its velocity is
A. entirely vertical.
B. entirely horizontal.
C. both vertical and horizontal.
D. There's not enough information given to determine.
B. entirely horizontal.
At what part of a path does a projectile have maximum speed?
A. When it is thrown
B. Half-way to the top
C. At the top of its path
D. When it returns to the ground
E. Both a and d
E. Both a and d
A ball is thrown straight upward at 10.0 m/s. Ideally (no air resistance), the ball will return to the thrower's hand with a speed of
A. 40.0 m/s.
B. 20.0 m/s.
C. 10.0 m/s.
D. 0 m/s.
A. 40.0 m/s.
An object is dropped and falls freely to the ground with an acceleration of 9.8 m/s2. If it is thrown upward at an angle instead, its acceleration would be
A. 0 m/s2
B. 9.8 m/s2downward.
C. 9.8 m/s2 upward.
D. larger than 9.8 m/s2
E. none of the above
B. 9.8 m/s2downward.
After a rock that is thrown straight up reaches the top of its path and is starting to fall back down, its acceleration is (neglect air resistance)
A. 0 m/s2
B. 4.9 m/s2
C. 9.8 m/s2
D. 19.6 m/s2
C. 9.8 m/s2
A ball thrown in the air will never go as far as physics ideally would predict because
A. one can never throw the ball fast enough.
B. gravity is acting.
C. ideally the ball would never land.
D. air resistance slows the ball.
D. air resistance slows the ball.
What are the components of a vector with a magnitude of 28.0 and an angle of 75�?
A. Vx = -7.25, Vy = 27.0
B. Vx = 7.25, Vy = 27.0
C. Vx = 27.0, Vy = 7.25
D. Vx = 27.0, Vy = -7.25
E. Vx = -27.0, Vy = -7.25
B. Vx = 7.25, Vy = 27.0
Human reaction time is usually about 0.20 s. If your lab partner holds a ruler between your finger and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it? (Disregard air resistance. g = 9.81 m/s2.)
A. at le
D. at least 19.6 cm
A rifle with a muzzle velocity of 100 m/s is fired horizontally from a tower. Neglecting air resistance, where will the bullet be 1 second later?
A. 50 m downrange
B. 98 m downrange
C. 100 m downrange
D. 490 m downrange
E. none of the above
C. 100 m downrange
As an object falls freely in a vacuum, its
A. velocity increases.
B. acceleration increases.
C. both a and b
D. none of the above
A. velocity increases.
. If you lift two loads up one story, how much work do you do compared to lifting just one load up one story?
A) Four times as much
B) Twice as much
C) The same amount
D) One half as much
E) One quarter as much
B) Twice as much
Power is defined as the
A) force on an object times the distance the object moves.
B) force on an object divided by the time the force acts.
C) work done on an object divided by the time taken to do the work.
D) work done times the time it takes to do tha
C) work done on an object divided by the time taken to do the work.
. Potential energy is the energy an object has because of its
A) speed.
B) location.
C) size.
D) temperature.
E) density.
B) location.
4. Kinetic energy of an object is equal to
A) one half the product of its mass times its speed squared.
B) one half the product of its mass times its speed.
C) its mass multiplied by its speed.
D) its mass multiplied by its acceleration.
E) its mass multi
A) one half the product of its mass times its speed squared.
. How much farther will a car traveling at 100 km/s skid than the same car traveling at 50 km/s?
A) Five times as far
B) Four times as far
C) Twice as far
D) The same distance
E) Half as far
B) Four times as far
6. An arrow in a bow has 70 J of potential energy. Assuming no loss of energy due to heat, how much kinetic energy will it have after it has been shot?
A) 140 J
B) 70 J
C) 50 J
D) 35 J
E) 0 J
B) 70 J
Energy is changed from one form to another with no net loss or gain.
A) Always true
B) Sometimes true
C) Always false
A) Always true
8. A job is done slowly, and an identical job is done quickly. Both jobs require the same amount of work but different amounts of
A) energy.
B) power.
C) both a and b
D) none of the above
B) power.
9. A ball is thrown into the air with 100 J of kinetic energy which is transformed to gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is
A) less than
A) less than 100 J.
10. Two physics students, Will N. Andable and Ben Pumpiniron, are in the weightlifting room. Will lifts the 100-pound barbell over his head 10 times in one minute; Ben lifts the 100-pound barbell over his head 10 times in 10 seconds. Which student does th
C) They both do the same amount of work
11. Using the information from question 11, which student delivers the most power?
A) Will does
B) Ben does
C) They both use the same amount of power
B) Ben does
12. During a physics lab, Jack and Jill ran up a hill. Jack is twice as massive as Jill; yet Jill ascends the same distance in half the time. Who did the most work?
A) Jack
B) Jill
A) Jack
A tired squirrel (mass of approximately 1 kg) does push-ups by applying a force to elevate its center-of-mass by 5.0 cm in order to do a mere 0.50 Joule of work. If the tired squirrel does all this work in 2.0 seconds, then determine its power.
a. 5 J b.
c. 0.25 W
2.) When doing a chin-up, a physics student lifts her 42.00 kg body a distance of 0.2500 meters in 2.000 seconds. What is the work done by the student's biceps?
a. 10.5 N b. 102.9 J c. 102.9 W d. 51.45 W
b. 102.9 J
3.) Ben Travlun carries a 200. N suitcase up three flights of stairs, a height of 10.0 m, and then pushes it with a horizontal force of 50.0 N at a constant speed of 0.500 m/s for a horizontal distance of 35.0 meters. How much work does Ben do on his suit
b. 3750 J
4.) A 60. kg skydiver leaps out of an airplane at an altitude of 2000. m. Assuming an initial velocity equal to zero and neglecting air resistance, what would be his speed at an altitude of 1000. m using the conservation of mechanical energy?
a. 140 m/s b
a. 140 m/s
An 80.0 kg baseball player begins a slide into third base when moving at a speed of 5.00 m/s. The coefficient of friction between his body and the dirt is 0.650. He slides such that he stops just as he reaches the base.
5.) How far did he slide?
a. 5.0 m
c. 1.96 m
An 80.0 kg baseball player begins a slide into third base when moving at a speed of 5.00 m/s. The coefficient of friction between his body and the dirt is 0.650. He slides such that he stops just as he reaches the base.
6.) How much work was done by frict
b. 1020 J
which one of the following steps is NOT part of the scientific method?
a) make a guess about the answer and predict its consequences
b) repeat the experiments until the answers match the predictions
c) formulate a general rule based on the predictions and
B
a scientific hypothesis may turn out to be right or it may turn out to be wrong. If it is a valid hypothesis, there must be a test proving that it is _________
wrong
Speed is
a) the distance covered per unit of time
b) a measure of how fast something is moving
c) always measured in terms of a unit of distance by a unit of time
d) all of the above
e) none of the above
D
When you look at the speedometer in a moving car, you can see the car's _______
instantaneous speed
If you are in a car that is going around a curve and the speedometer reads a constant 30 mph, which of the following is NOT true?
a) your acceleration is constant
b) your direction is constantly changing
c) your speed is constant
d) you and the car are ac
E
As an object falls freely in a vacuum, its
a) acceleration increases
b) velocity increases
c) both A and B
B
a ball is thrown upwards and caught when it comes back down, in the absence of air resistance, the speed of the ball when caught would be _________
the same
when a basketball player jumps to make a shot, once the feet are off the floor, the jumper's acceleration is _______
9.80 m/s sqaured
a bacll is thrown straight up. At the top of its path, its acceleration is _________
9.80 m/s squared
a car accelerates at 2 m/s squared. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 30 m/s
15 s
ten seconds after starting from rest, a freely falling object will have a speed of about ____
100 m/s
A vector is a quantity that has ________
magnitude and direction
which of th following would NOT be considered a projectile?
a) a cannonball after rolling off the edge of a table
b) a cannonball thrown through the air
c) a cannonball rolling down a slope
d) a cannonball thrown straight up
bD
In the absence of air friction, the vertical componenet of a projectile's velocity doesn't change as the projectile moves
Always false
at the instant a ball is thrown horizaontally, an identical ball is dropped from the same height. Which ball hits the ground first?
same
In the absence of air resistance, the angle at which a thrown ball will go the farthest is ____
45 degrees
At what part of a path does a projectile have minimum speed?
top of path
A projectile launched horizontally hits the ground in 0.5 seconds. If it hade been launched with a much higher sped in the same direction, it would have hit the ground (neglecting the earth'ss curvature and air resistance) in
0.5s
A projectile is fired horizontally in a vacuum. The projectile maintains its horizontal component of speed because
a) it is not acted on by any forces
b) it has not vertical component of speed to begin with
c) the net force acting on it is zero
d) it is n
D
A cannonball is launched horizontally from a tower. If the cannon has a barrel velocity of 100 m/s, where will the cannonball be 1 second later? (neglect air resistance)
100m
Jose can jump vertically 1 meter from his skateboard when it is at rest. When the skateboard is moving horizontally, Jose can jump ___________
1m
What is the resultant of a 4-unit vector at right angles to each other?
5 units, by 3-4-5 relationship
At the instant a ball is thrown horizontally, an identical ball is dropped from the same height. Which ball hits the ground first?
same
in the absence of air resistance, the angle at which a thrown ball will go the farthest is _______
45 degrees
A cannon with a barrel velocity of 100 m/s launches a cannonball horizontally from a tower. Neglecting air resistance, where will the cannonball be 1 s later?
100m
The law of inertia applies to
a) both moving and nonmoving objects
b) moving objects
c) objects at rest
A
If the force of gravity suddenly stopped acting on the planets, they would do what?
straight line target, to orbit
One object has twice as much mass as another object. The first object also has twice as much
a) inertia
b) gravitational acceleration
c) energy
d) velocity
A
Compared to its mass on earth, the mass of a 10 kg object on the moon is
a) more
b) less
c) the same
C
An object following a straight-line path at constant speed
a) has zero acceleration
b) has no forces acting on it
c) must be moving in a vacuum
d) has a net force acting on it in the direction of motion
A
equilibrium occurs when
a) the net force on the object is zero
b) all the forces acting on an object are balanced
c) the sum of the upward forces equals the sum of the downward forces
d) the sum of the +x forces on an object equals the sum of the -x force
E
what is the maximum resultant possible when adding a 3N force to an 8N force
11N
if you hang from two strands of a vertical clothesline, the tension in each line will be half your weight. if the lines are not vertical, but are at equal angles from the vertical, the tension in each is
greater
Which has more mass, a kilogram of feathers or a kilogram of iron?
same mass
a certain bag of groceries has a mass of 10 kilograms and a weight of about______
100N
an object weighs 30 N on earth. a second object weighs 30 N on the moon. Which has the greater mass?
on the moon
Accelerations are produced by________
forces
The accelerations produced by a net force on an object is
a) in the same direction as the net force
b) directly proportional to magnitude of the net force
c) inversely proportional to the mass of the object
d) all of the above
D
A heavy person and a light person parachute together and wear the same size parachute. assuming they open their parachutes at the same time, which person reaches the ground first?
A heavy person
Compared to its weight on earth, a 10 kg object on the moon will weigh ________
less
An apple weighs 1 N. When held at rest on your head, the net force on the apple is _______
O
A girl pulls on a 10 kg wagon with a constant force of 30 N. What is the wagon's acceleration?
3 m/s squared
A rock is thrown vertically into the air. At the very top of its trajectory, the net force on it is ____________
gravity
Pressure is defined as ___________
Force per unit area
which of the following would exert the most pressure on the ground?
a) A woman standing on skis
b) a woman standing in running shoes
c) a woman standing in high heels
c
As Bob falls from a high-flying stationary helicopter, his velocity increases and his acceleration ____________
decreases
If the force acting on a cart doubles, what happens to the acceleration of the cart?
doubles
A 10 N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is ____________
6 N
A tow truck exerts a force of 3000 N on a car, accelerating it a 2 m/s squared. What is the mass of the car?
a) 1000 kg
b) 3000 kg
c) 1500 kg
d) 500 kg
c
How much force is needed to accelerate a 2kg physics book to an acceleration of 6 m/s squared?
12 N
A 10 N falling object encounters 10 N of air resistance. The magnitude of the net force on the net force of the object is ________
0
A high school student hits a nail with a hammer. During the collision, there is a force
a) on the hammer, but not on the nail
b) on both
c) on the nail, but not on the hammer
B
A player hits a ball with a bat. The action force is the impact of the bat against the ball. What is the reaction to this force?
Ball on the bat
A bug splatters on the windshield of a moving car. Compared to the force of the car on the bug, the force of the bug on the car is ___________
the same
If a horse pulls a wagon at rest, the wagon pulls back equally as much on the horse. Will the wagon be set into motion?
a) yes, because there is a net force acting on the wagon
b) yes, because there is a time delay between action and reaction
c) yes, the
A
According to Newton's third law, of you push gently on something, it will _________
push gently back
A rocket is able to accelerate in the vacuum of space when it fires its engines. The force that propels the rocket is the force ____________
gas on rocket
A woman weighing 500 N sits on the floor. She exerts a force on the floor of __________
500N.
Two people pull on a rope in a tug-of-war. Each pulls with 400 N of force. What is the tension in the rope?
400 N
Which has more momentum, a large truck moving at 30 mph, or a small truck moving at 30 mph.
large truck, p = mv
If the momentum of an object changes and its mass remains constant,
a) there is a force acting on it
b) the velocity is changing
c) its is accelerating or decelerating
d) all of the above
D
In order to increase the final momentum of a golf ball, we could
a) follow through with hitting the ball
b) increase the time of contact with the ball
c) increase the force acting on the ball
d) swing as hard as possible
e) all of the above
E
Momentum of a system is conserved only when
a) there are no forces acting on the system
b) the system is not moving
c) there are no internal forces acting on the system
d) there is not external forces acting on the system
e) the system has zero momentum
D
Which of the following has the largest momentum?
a) a dog running down the street
b) a tight-rope walker crossing Niagara Falls
c) the science building at your school
d) a pickup truck traveling down a highway
e) a mack truck parked in parking lot
D
A cannon recoils from launching a cannonball. The speed of the cannon's recoil is small because the
a) momentum of cannon is unchanged
b) impulse on the cannon is less than the impulse on the cannonball
c) cannon has far more mass than the cannonball
d) F
C
In order to catch a ball, a baseball player moves his or her hand backwards in the direction of the balls motion, doing this reduces the force of impact on the player's hand. Principally, because ___________
increases force, reduces time
The force of an apple hitting the ground depends upon
a) the time of impact with the ground
b) air resistance on the apple as it falls
c) whether or not the apple bounces
d) the speed of the apple just before it hits
e) all of the above
E
Recoil is noticeably if we throw a heavy ball while standing on roller skates. If instead we go through the motions of throwing the ball but hold on to it, our net recoil velocity will be
a) the same as before
b) 0
c) small, but noticeable
B
A karate expert executes a swift blow and severs a cement block with her bare hand.
a) the force on both the block and the expert's hand have the same magnitude
b) the impulse on both the block and the expert's hand have the same magnitude
c) the tim of t
D
A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both are set in motion with the combined momentum that is ______
1 unit
Superman is at rest in space when he throws an asteroid that has more mass than he does. Which moves faster, Superman or the asteroid?
Superman
A 2kg ball is thrown at 3m/s. What is the ball's momentum?
6 (velocity x mass)
A 1 kg chunk of putty moving at 1 m/s collides with and sticks to a 5 kg bowling ball that is initially at rest. The bowling ball with his putty passenger will then be set in motion with a momentum of ________
1 m/s
If Nellie Newton pushes an object with 2x the force for 2x the distance, she does
a) four times the work
b) 8x the work
c) 2x the work
d) the same work
A
Power is defined as the
a) force on an object divided by the time as the force acts
b) work done on an object divided by time taken to do the work
c) work done times time taken to do that work
d) distance divided by the time taken to do the distance
e) fo
B
Potential energy is the energy an object has because of its_____________
location
Kinetic energy of an object is equal to _______
1/2 m rsquared
an object that has linear kinetic energy _______
moving
a job is done slowly and an identical job is done quickly. Both jobs require the same amount of work, but different amounts of ________
power
Which has a greater kinetic energy? A car traveling at 30 kph, or a half as massive car traveling at 60 kph?
Car at 60 kph
An object at rest may have
a) momentum
b) velocity
c) energy
d) speed
C
How much power is required to do 100J of work on an object in 2s?
50 watts (P= w/t)
How much work is done on a 50N rock that you lift 10m?
500J
It takes 40J to push a large box 4m across the floor. Assuming the push is in the same direction as the move, what is the magnitude of the force on the box?
10m (W/D)
Which has greater angular speed?
a) a horse near the inside rail of a merry go-round
b) neither, same angular speed
c) the outside rail
B
If you whirl a tin can on the end of a string, and the string suddenly breaks, the can will
a) fly off tangent to its circular path
b) fly directly towards you
c) directly away from you
d) spiral in towards your hand
e) spiral away from your hand
A
Car travels in a circle with constant speed. The net force on the car is ________
inward
Nellie Newton swings a rock into a circular path while holding an attached string overhead. The string makes a 45 degree angle to the vertical (comprising a "conical pendulum"). The centripetal force that holds the rock in its circular path is the
a) hori
A
In which of the following is the center of gravity located at a point where there is no mass?
a) cookie
b) pineapple
c) donut
d) glass of milk
e) apple
C
If an object is in unstable equilibrium, any displacement will _______________
topple, lower the CG
the center of mass of a human body is located at the point
a) fixed, though different for different people
b) that changes as a person bends over
c) that is always just below the belly button
B
a ball resting on the floor is in what kind of equilibrium?
neutral
the resistance an object has to changes in its rotational state of motion is called rotational _________
inertia
which has more rotational inertia? a girl running with her legs bent, or the same girl running with her legs straight?
girl with legs straight
angular momentum is defined as
a) rotational inertia times the linear velocity
b) mass times velocity momentum times rational velocity
c) none of the above
C
Suppose a huge rotating cloud of particles in space gravitates together to form a dense ball. As the cloud shrinks in size, the cloud rotates ________
faster
A ring and a disk of the same radius roll down a hill together. Which reaches the bottom first?
disk
The action of the tides is slowing the spin of earth over time, reducing its angular momentum. What must be true?
a) the tides are speeding up
b) the moon is gaining angular momentum
c) the moon is getting closer to earth
B
the orange and black speed signs posted on freeway interchanges is not a speed limit, but
a) don't spill your coke speed
b) speed required to match the bank angle of the curve with the automobiles centripetal acceleration
c) the speed that will prevent sk
D
The total momentum of the universe is _________
0
When you look at the speedometer in a moving car, you can see the car's:
a. average distance traveled
b. instantaneous acceleration
c. average speed
d. instantaneous speed
e. average acceleration
d. instantaneous speed
Acceleration is defined as the change in:
a. time it takes to move from one place to anothr place
b. velocity of an object
d. distance divided by the time interval
d. velocity divided by the time interval
e. time it takes to move from one speed to another
d. velocity divided by the time interval
If a moving object changes the direction of its motion, which of these must also change?
a. mass of the object
b. speed of the object
c. weight of the object
d. velocity of the object
d. velocity of the object
Suppose you take a trip that covers 180 km and takes 3 hours to make. Your average speed is:
a. 30km/h
b. 60km/h
c.180km/h
d.360km/h
e.540km/h
e. 540 km/h
Henry performs an experiment using four balss with different masses but the same diameter. He drops the ball from a height of 4 meters. He notes the time each ball takes to reach the ground. Which variable has henry changed in his experiment?
a. mass of t
a. mass of the ball
A student dropped a quarter into a canyon. The quarter fell 20meters and took approximately 2 seconds to strike the ground. What was the approximate average speed of the quarter as it fell?
a. 10 m/s
b. 18m/s
c. 22m/s
d. 44m/s
a. 10 m/s
Estella wants to find her average speed during a bike ride. How should she find her average speed?
a. divide the distance she traveled by the time her ride took
b. divide the time her ride took by the distance she travled
c. multiply the distance she trav
a. divide the distance she traveled by the tme her ride took
One possible unit for speed is
a. miles per hour
b. meters per second
c. kilometers per hour
d. all of the above
e. none of the above
d. all of the above
A car is traveling at a speed of 36 km/h. It speeds up to 72 km/h in 5.0 seconds. What is the acceleration fo the car?
a. 2.0 m/s^2
b. 4.0m/s^2
c. 7.2m/s^2
d. 10m/s^2
c. 7.2m/s^2
Samantha is driving a car at a speed of 10m/s. She accelerates for 5 seconds, and her new speed is 15m/s. What is the acceleration of the car?
a. 1m/s^2
b. 2m/s^2
c. 3m/s^2
d. 5m/s^2
a. 1m/s^2
A train begins moving up a steep hill at a speed of 30m/s. It decelerates for 3 minutes until its speed reduces to 25m/s. Which of these is the approximate acceleration?
a. 36m/s^2
b. 0.139 m/s^2
c. -0.028m/s^2
d. -5m/s^2
c. -0.028m/s^2
A ball is thrown straight up. At the top of its path its instaneous speed is:
a. 0m/s
b. about 5 m/s
c. about 10m/s
d. about 20 m/s
e. about 50m/s
a. 0 m/s