Question

An object moving with a speed v0 collides head-on with a second object initially at rest. A student assumes the collision is elastic and calculates the speeds of the two objects and the speed of the center of mass of the objects after the collision. If the student assumes the collision was perfectly inelastic, how would that change the way the student calculated the list values?
A. The student only uses conservation of kinetic energy for inelastic collisions, but used both conservation of kinetic energy and momentum for elastic collisions
B. The student only uses conservation of momentum for inelastic collisions, but used both conservation of kinetic energy and momentum for elastic collisions
C. The student only uses conservation of kinetic energy for the final speeds of the two objects in inelastic collisions, but only uses conservation of momentum for speed of the center of mass
D. The student only uses conservation of momentum for the final speeds of the two objects in inelastic collisions, but only uses conservation of kinetic energy for speed of the center of mass
E. The student only uses conservation of momentum for the final speeds of the two objects in elastic collisions, but only uses conservation of kinetic energy for speed of the center of mass

Answer 1

Answer:B

Explanation:

It is given that the first collision is elastic so we can conserve momentum as well as the kinetic energy of the system.

The value of the coefficient of restitution is equal to one for an elastic collision. An elastic collision is also called a perfectly Elastic collision.

A perfectly inelastic collision is one in which there is the loss of kinetic energy and some of the kinetic energy is converted into another form of energy, for example, internal energy.

although momentum is conserved in Inelastic collision kinetic energy is not conserved.