Question

In collisions between two objects, kinetic energy is conserved only

a) if one of the objects was initially at rest.
b) if potential energy converts to work.
c) in inelastic collisions.
d) in elastic collisions.

Answer 1

Kinetic energy is conserved in an elastic collision where objects bounce off each other without losing energy. In an inelastic collision, kinetic energy is transformed into other forms of energy and is not conserved.

Step-by-step explanation:

In the context of collisions between two objects, kinetic energy is conserved in an elastic collision. In an elastic collision, the objects collide and bounce off each other without any loss of kinetic energy in the form of other types of energy, such as heat or sound. In contrast, an inelastic collision involves a change in kinetic energy, where some of the kinetic energy is transformed into other forms of energy, and the objects may stick together or deform.

Conservation of momentum is a principle that applies to both elastic and inelastic collisions. However, conservation of kinetic energy is unique to elastic collisions. Therefore, the correct answer to the question 'In which type of collision is kinetic energy conserved?' is option (d) in elastic collisions.