Question

An object moving on a horizontal, frictionless surface makes a glancing collision with another object initially at rest on the surface. In this case which of the following is true about momentum and kinetic energy? 4A) Momentum is always conserved, and kinetic energy may be conserved. (B) Kinetic energy is always conserved, and momentum may be conserved. (C) Momentum is always conserved, and kinetic energy is never conserved. (D) Both momentum and kinetic energy are always conserved. (E) Neither momentum nor kinetic energy is conserved.

Answer 1

Answer:

The correct answer is option 'a' 'The momentum is always conserved while as the kinetic energy may be conserved'

Explanation:

The conservation of momentum is a basic principle in nature which is always valid in an collision between 'n' number of objects if there are no external forces on the system. It is valid for both the cases weather the collision is head on or glancing or weather the object is elastic or inelastic.

The energy is only conserved in a collision that occurs on a friction less surface and the objects are purely elastic. Since in the given question it is mentioned that only the surface is friction less and no information is provided regarding the nature of the objects weather they are elastic or not hence we cannot conclusively come to any conclusion regarding the conservation of kinetic energy as the objects may be inelastic.