Linear Momentum unit test
A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.
Deciding whether momentum is conserved
Ballistic pendulum sequence
Momentum and impulse as integrals
Two-dimensional collisions
Center of mass
Kinetic energy lost in a collision
Elastic collision special cases
Variable-mass systems
Elastic collision in one dimension
Momentum conservation with a pivot
Impulse-momentum in two dimensions
Rocket equation qualitatively
Short answer 1. Define or explain: Conservation of momentum
3 ptsShort answer 2. Define or explain: Center of mass by integration
3 ptsShort answer 3. Define or explain: Motion of the center of mass
3 ptsShort answer 4. Define or explain: Perfectly inelastic collision
3 ptsFree response
10 ptsA 2.0 kg cart rests on a frictionless horizontal track. Starting at t = 0 a horizontal force F(t) = (6 N/s²)t² acts on it for 2.0 s.
Starting from Newton’s second law, show that the impulse delivered equals ∫F dt, and calculate that impulse.
Determine the cart’s speed at t = 2.0 s.
The cart then collides with and sticks to a stationary 6.0 kg cart. Determine the velocity of the pair after the collision.
Determine the kinetic energy lost in the collision and explain where that energy goes.
Determine the impulse delivered to the 6.0 kg cart during the collision and state how it compares with the impulse delivered to the 2.0 kg cart.
State the velocity of the center of mass of the two carts immediately before and immediately after the collision.