In The Preceding Question Which Case Requires The Greatest Impulse

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

Answer: The moving skateboard.

Question: Distinguish between force and impulse.

Answer: Impulse is force times a time interval.

Question: An impulse can be increased by

Answer: increasing the force or increasing the time interval.

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

Answer: The force is applied for a longer time in the long cannon.

Question: How is the impulse -momentum relationship related to Newton’s second law?

Answer: F=ma=mΔv/Δt,

so Ft=Δ(mv)

Question: To impart the greatest momentum to an object, you must:

Answer: exert the greatest force over the longest time.

Question: When you are struck by a moving object, is it favorable that the object makes contact with you over a short time or over a long time?

Answer: Long contact time decreases the magnitude of the average force and is favorable.

Question: Why is a force that is applied for a short time more effective in karate?

Answer: The average force is increased.

Question: Why is it advantageous to roll with the punch in boxing?

Answer: Rolling with the punch increases contact time, which decreases the force.

Question: Which undergoes the greatest change in momentum (if all of the baseballs have the same speed just before being caught and just after being thrown)?

In the preceding question, which case requires the greatest impulse?

Answer: For both questions:

A baseball that is caught and then thrown back