Statement I: No external force acts on a system of two spheres which undergo a perfectly elastic head-on collision. The minimum kinetic energy of this system is zero if the net momentum of the system is zero.
Statement II: If any two bodies undergo a perfectly elastic head-on collision, at the instant of maximum deformation. the complete kinetic energy of the system is converted to' deformation potential energy of the system.

Options

A. Both assertion and reason are true and reason is the correct explanation of assertion.
B. Both assertion and reason are true but reason is not the correct explanation of assertion.
C. Assertion is true and reason is false.
D. Assertion is false and reason is true.

Answer

C

Explanation

For a system of two isolated spheres having non-zero initial kinetic energy, the complete kinetic energy can be convened to other forms of energy if the momentum of the system is zero. This is due to the fact that for an isolated system, the net momentum remains conserved. If an isolated system has non-zero momentum, for the momentum to remain constant, complete kinetic energy of the system cannot become zero. Hence, Statement I is true while Statement II is false.