Question

A car, mass m1 is moving to the right on a frictionless air track. It collides with a second car, mass m2, which is initially at rest. Which of the following statements are true? (If A and E are true, and the others are not, enter TFFFT).

A) If car 1 is much lighter than m2, and the collision is perfectly elastic, car 1 will continue heading to the right with nearly its original speed after the collision.

B) If car 1 sticks to car 2, the final total kinetic energy of the car1-car2 system is less than the initial total kinetic energy of the two cars.

C) If the collision is elastic, car 1 will never come to a stop after the collision.

D) Suppose (for this statement only) that car 2 was NOT initially at rest, but was instead heading towards car 1 with equal (but opposite) momentum before the collision. After the collision, the cars must both be at rest.

E) If car 1 sticks to car 2, the car1-car2 system must be at rest after the collision.

Answer 1

Answer will be FTFTF

A) It is False. If car1 is much lighter than car2 it will come to rest after collision.

B) Total energy of the system will be less than initial energy due to loss of energy during inelastic collision. Hence True

C) Even for elastic collision Car1 will come to a stop if m1=m2. Hence False

D) By law of conservation of momentum total momentum before and after collision should be conserved. hence True.

E) Not true for all cases. Hence False.