Chapter 5 Momentum

The difference between impulse and impact force involves the

• distance the force acts

• time the force acts

• difference between acceleration and velocity

• mass and its effect on resisting a change in momentum

Recoil is noticeable if we throw a heavy ball while standing on roller skates. If instead we go through the motions of throwing the ball but hold onto it, our net recoil will be _____

• zero

• the same as actually throwing the ball

• small, but noticeable.

Newton's second law of motion explains acceleration. What is the mathematical formula for acceleration? a= ____

• distance/time

• mass/force

• force/mass

• speed/time

A 4 kg ball has the momentum of 20 kg m/s.  What is the ball's speed?

• 80 m/s

• 5 m/s

• 16 m/s

A ball is traveling 5 m/s and has a momentum of 40 kg m/s.  What is the mass of the ball?

• 200 kg

• 5 kg

• 8 kg

• 35 kg

The average momentum of a 90 kg runner who covers 100 m in 10s is (Hint - how do you calculate momentum?)

• 9000 kg m/s

• 600 kg m/s

• 900 kg m/s

• 9 kg m/s

Answer explanation

Momentum is mass x velocity.

Here you need to figure out the velocity first then multiply by the mass.

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has 4 times as much mass, its momentum is

• zero

• doubled

• quadrupled

• unchanged

Two billiard balls having the same mass roll toward each other, each moving at the same speed. What is the combined momentum of the two balls?

• Not enough informaiton to answer the question

• zero

• 2 times the mass

• 2 times the mass x velocity

Consider massive gliders that slide along a friction-free horizontal air track. Glider A has a mass of 1 kg, a speed of 1 m/s and it collides with glider B, which has a mass of 5 kg and is at rest. If they stick upon collision, their speed after collision will be? What is the best way to set up this problem

Compared with falling on a wooden floor, a wine glass may not break when it falls to a carpeted floor because of thealling on a wooden floor, a wine glass may no

• lesser impulse in stopping

• longer time to stop