GINO PHYSICS REVIEW 4

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