Question

Elastic collisions are said to conserve the total kinetic energy, while inelastic collisions result in some loss of energy. Provide and describe a real-life example of each type. Indicate where you think the lost energy went to for your inelastic example.

Answer 1

A perfectly elastic collision is defined as one in which there is no loss of kinetic energy in the collision. An inelastic collision is one in which part of the kinetic energy is changed to some other form of energy in the collision. Any macroscopic collision between objects will convert some of the kinetic energy into internal energy and other forms of energy, so no large scale impacts are perfectly elastic. Momentum is conserved in inelastic collisions, but one cannot track the kinetic energy through the collision since some of it is converted to other forms of energy. Collisions in ideal gases approach perfectly elastic collisions, as do scattering interactions of sub-atomic particles which are deflected by the electromagnetic force. Some large-scale interactions like the slingshot type gravitational interactions between satellites and planets are perfectly elastic.

A popular demonstration of conservation of momentum and conservation of energy features several polished steel balls hung in a straight line in contact with each other. If one is pulled back and allowed to strike the line, one ball flies out the other end. If two balls are sent in, two come out, and so forth...

examples of an elastic collision

When we throw a ball on the floor, it bounces back. This is an example of elastic collision where both momentum and kinetic energy are conserved.

The collision between the atoms is also an example of elastic collision.

The collision between two billiard balls is an example of elastic collision.

Examples of inelastic collision

Car crash : the car crashing against the tree is the example of inelastic collision as the kinetic energy is not conserved here. The car stops

The collision between two objects such that after the collision both stick to each other and hence move with the same velocity.
                                                 

The bullet hitting wood is also an example of inelastic collision. The kinetic energy is not conserved in this case also.

Seat belt tied to a person and the sudden application of breaks is also an example of inelastic collision.

the energy is converted to other form in case of inelastic collision. in most parts energy is dessipated in the form of heat in inelastic collision.