Momentum Basics
Momentum depends on which quantities?
A) mass only
B) velocity only
C) mass and velocity
D) force and time
C) mass and velocity
Impulse equals change in __________.
momentum
In a closed system, what is conserved in collisions?
A) velocity
B) force
C) momentum
D) acceleration
C) momentum
Work is calculated as:
A) FΔt
B) Fd
C) mv
D) ma
B) Fd
Gravitational potential energy near Earth is:
A) mv
B) mgh
C)(1/2)mv^2
D) Fd
B) mgh
Momentum is often described as “inertia in ______.”
motion
Impulse can be calculated as:
A) mv
B) Fd
C) FΔt
D) ma
C) FΔt
In a perfectly inelastic collision, objects ______.
stick/move together
If force and displacement are in the same direction, work is ______.
positive
If net work is positive, kinetic energy ______.
increases
A 2 kg cart moves at 3 m/s to the left. What is its momentum?
-6 Ns
A 4 N force acts for 3 s. What is the impulse?
12 Ns
A 2 kg cart moving at 4 m/s hits a 2 kg cart at rest and sticks. Final velocity?
2 m/s
A force acts perpendicular to motion. Work done is:
A) positive
B) negative
C) zero
D) depends
C) zero
An object falls. Gravity does what kind of work?
A) positive
B) negative
C) zero
D) depends
A) positive
Which has greater momentum?
A) 1 kg at 10 m/s
B) 2 kg at 5 m/s
C) They are equal
D) Cannot determine
C) They are equal
A cart’s momentum changes from 5 kg·m/s to 1 kg·m/s (same direction). The impulse is:
A) +6
B) -4
C) +4
D) -6
B) -4
After a collision, total momentum is:
A) always zero
B) always greater
C) always conserved
D) sometimes lost
C) always conserved
Which forces can do negative work?
A) friction
B) gravity (object moving up)
C) applied force in direction of motion
D) tension opposing motion
A) friction
B) gravity (object moving up)
D) tension opposing motion
In a system where only gravity does work:
A) Total mechanical energy is conserved
B) KE increases as PE decreases
C) PE increases as KE increases
D) Motion must stop
A) Total mechanical energy is conserved
B) KE increases as PE decreases
Which changes will increase momentum?
A) Increase mass
B) Increase velocity
C) Reverse direction
D) Reduce velocity magnitude
A) Increase mass
B) Increase velocity
Which increase impulse?
A) Larger force
B) Longer time
C) Smaller force over shorter time
D) Larger change in momentum
A) Larger force
B) Longer time
D) Larger change in momentum
Which are true for 1D collisions?
A) Momentum is conserved
B) Objects must bounce
C) Final velocity can be zero
D) Direction matters
A) Momentum is conserved
C) Final velocity can be zero
D) Direction matters
A 10 N force pushes an object 5 m forward. Work done?
50 J
A 2 kg object is lifted 5 m. What is its gravitational potential energy?
100 J