Final Exam - Momentum, Uniform Circular Motion, & Gravitation

What is the product of an object's mass and velocity?

• Momentum

• Impulse

• Force

• Acceleration

In which type of collision is kinetic energy conserved?

• Perfectly inelastic collision

• Inelastic collision

• Elastic collision

• None of the above

What force causes uniform circular motion?

• Tension force

• Gravitational force

• Frictional force

• Centripetal force

What is the measure of how fast an object is rotating around a specific point?

• Rotational angle

• Angular velocity

• Centripetal acceleration

• Gravitational field

A 5 N force is applied to a 3 kg ball to change its velocity from +9 m/s to +3 m/s. The impulse on the ball is ______ N·s.

• -2.5

• -10

• -18

• -45

A constant force of 4.5 N acts on a 7.2-kg object for 10.0 s. What is the change in the object's momentum?

• 45 kg m/s

• 72 kg m/s

• 32.4 kg m/s

• 0.45 kg m/s

Which object listed below has the greatest momentum?

• A 0.05 kg object rolling at 0.2 m/s.
• A 0.15 kg object rolling at 2 m/s.
• A 0.15 kg object rolling at 1 m/s
• A 0.4 kg object rolling at 2 m/s.

Which of the following are equal to the impulse, J? Select TWO answers.

• Ft

• at

• p

Answer explanation

Impulse, J, can be calculated in either of two ways:

Impulse is equal to the change in an object’s momentum.

Impulse is equal to the force experienced multiplied by the time interval of collision, J = Ft

A 10,000 kg railroad car traveling at a velocity of 6 m/s hits a stationary (at rest) boxcar that weighs 5600 kg. At what speed will the second boxcar move if the railroad car reduces its speed to 4.0 m/s after collision?

• 5.0 m/s

• 3.6 m/s

• 7.8 m/s

• 9.8 m/s

What would act as the centripetal force for a car on a circular track?

• Friction

• Gravitation

• Tension

• None of These