What is meant by elastic and inelastic collision?

# What is meant by elastic and inelastic collision?

The collision in which total linear momentum and total K.E. is conserved is called elastic collision.

i.e. In elastic collision,

m

_{1}u_{1}+ m_{2}u_{2}= m_{1}v_{1}+ m_{2}v_{2}

½(m

_{1}u_{1}^{2}+ m_{2}u_{2}^{2}) = ½(m_{1}v_{1}^{2}+ m_{2}v_{2}^{2})

Eg: Collision between atomic or sub-atomic particles, collision between gas molecules, etc.

The collision in the total linear momentum is conserved but the total K.E. is not conserved is called inelastic collision.

i.e. In inelastic collision,

m

_{1}u_{1}+ m_{2}u_{2}= m_{1}v_{1}+ m_{2}v_{2}

But,

½(m

_{1}u_{1}^{2}+ m_{2}u_{2}^{2}) ≠ ½(m_{1}v_{1}^{2}+ m_{2}v_{2}^{2})

Eg: A bullet embedded in a target is one example of inelastic collision.