The distance traveled by an object divided by the time it takes to travel that distance is called
average speed
In order to determine speed, you must know
time and distance
What is the speed of an object at rest?
0 km/h
The difference between speed and velocity is that velocity
includes direction
Which of the following does not indicate velocity?
28 km from Los Angeles to Catalina Island
Acceleration is defined as the change in velocity divided by
time
An airplane is flying at 635 km per hour at an altitude of 35 000 m. It is currently over Kansas and is approximately 16 minutes ahead of its scheduled arrival time. What is its velocity?
This cannot be determined without further information.
The SI unit for acceleration is
m/s2
On a velocity-time graph, a line with a negative slope indicates that the object is
slowing down
When the velocity of an object changes, it is acted upon by a(n)
force
The combination of all of the forces acting on an object is called the
net force
If the net force acting on a stationary object is zero, then the object will
remain at rest
If the net force on an object is zero then the object has
balanced forces
A tug-of-war that results in one team pulling the other across the line is an example of
unbalanced forces
Which of the following best illustrates balanced forces?
A stretched rubber band being held between two hands
Friction is defined as
force that opposes motion between two surfaces that are touching
A force is continuously applied to an object, causing it to accelerate. After a period of time, however, the object stops accelerating. What conclusion can be drawn?
The object is experiencing some kind of friction
Which of the following situations best demonstrates the effects of friction?
a parachutist descending to the ground
Which of the following statements is true?
Frictional forces are greatest when both surfaces are rough.
An object is in motion when
the object changes position relative to a stationary reference point.
Which is an example of kinetic friction?
friction between a car's windshield and the air as you drive into the wind
If the slope of a line on a distance-time graph is 1, the speed of the object being plotted is (Hint: Draw your own graph to visualize this idea)
constant
Which straight-line acceleration indicates an increase in speed?
4 m/s2
Which of the following speeds is the most accurate?
100 meters per second
How can the friction on a water slide be reduced?
run a constant stream of water down the slide
Which is an example of balanced forces acting on an object?
a leaf lying on the grass
A car is parked on a hill. In order to keep the car from rolling downhill, how great must the static friction acting on the car be? (Hint: Picture each scenario in your mind)
equal to the force pulling the car downhill
Which of the following is not a factor in calculating momentum?
acceleration
If you divide momentum by velocity, the result is the value of the object's
mass
Whenever an object is standing still, the value(s) that is/are always zero is/are
speed, momentum and velocity
Weight is best described as
the downward force exerted on objects due to gravity.
When objects are moved further apart from each other, the force of gravity
decreases.
Of the following, the greatest gravitational force would occur between
a loaded freighter on the high seas and Earth.
The law that states that every object maintains constant velocity unless acted on by an unbalanced force is
Newton's first law of motion.
The law that states that for every action force there is an equal and opposite reaction force is
Newton's third law of motion.
The SI unit of force, named for the scientist who described the relationship between motion and force, is called the
newton
One pound is equal to how many newtons?
4.448N
Which of the following equations is correct?
w = mg
When air resistance balances the weight of an object that is falling, the velocity
remains constant.
Earth pulls on the moon and holds the moon in its orbit. The moon pulls on Earth with an equal and opposite force. This is an example of
Newton's third law.
What is the unbalanced force that slows down a ball rolling across the floor?
the force of friction
If two objects with different masses and traveling with different velocities collide, what law allows you to predict the motion of the objects after the collision?
the law of conservation of momentum
Express the following as an equation: One newton is the force that can give an object with a mass of 1 kg an acceleration of 1 m/s2.
1 N = 1 kg 1 m/s2
Which statement about action-reaction forces is incorrect?
They always act on the same object.