Hewitt Ch 6 hw review

Which has a greater momentum: a heavy truck at rest or a moving skateboard?

• The heavy truck at rest.
• Both have zero momentum.
• Both have the same momentum.
• The moving skateboard.

Follow through is important in golf because it results in a greater

• force on the ball.
• force and impulse on the ball
• swinging motion.
• impulse on the ball.

A boxer rides with the punch so as to reduce

• impulse
• momentum
• speed
• force

Distinguish between force and impulse.

• Force is impulse times a time interval.
• Impulse is force per time interval.
• Force and impulse are the same.
• Impulse is force times a time interval.

An impulse can be increased by

• increasing the force or increasing the time interval.
• maintaining the force and decreasing the time interval.
• decreasing the force and maintaining time interval.
• decreasing the force and decreasing the time interval.

For the same force, why does a long cannon impart more speed to a cannonball than a short cannon?

• The force is applied for a longer time in the short cannon.
• The force is applied for a shorter time in the long cannon.
• The force is applied for a longer time in the long cannon.
• The force per unit time is greater for a long cannon.

A slowly moving ship can have a greater momentum than a fast-moving racing car when

• its mass is greater than the mass of the car
• its speed is greater than the speed of the car.
• it drifts toward a distant port.
• its mass times velocity is greater than that of the car.

The quantity that is called impulse can be measured by the

• product of force and time.
• how long the force acts compared to the amount of time
• difference between force and time.
• addition of force and time.

How is the impulse -momentum relationship related to Newton's second law?

• F=ma=mΔv/Δt , so F=Δ(mv)
• F=ma=mΔv/Δt, so Ft=Δ(mv)t
• F=ma=mΔvΔt, so F/t=Δ(mv)
• F=ma=mΔv/Δt, so Ft=Δ(mv)

To impart the greatest momentum to an object, you must

• exert the greatest force.
• exert the greatest force over the shortest time.
• exert the greatest force over the longest time.
• exert a force over the greatest time.