Two perfectly smooth elastic discs A and B, one k times as massive as the other, rest on a smooth horizontal table. The disc A is made to move towards B with velocity u and make a head on collision. Calculate the fraction of the kinetic energy transferred to B from A. Also show that the value of this fraction is the same whether B is k times as massive as A or vice versa.

Answer

`[(4k)/((k+1)^(2))]`