Body A of mass 4 m moving with speed u collides with another body B of mass 2 m at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by colliding body A is

Step-by-step solution

Energy transferred to B . Initial energy of B= zero Final velocity of aligned & v_B= ( m₂-m₁ m₁+m₂ ) u₂+ 2 m₁ u₁ m₁+m₂ & m₁=4 m, u₁=u & m₂=2 m, u₂=0 & v_B= 2(4 m) u 6 m = 4 3 u & 1 2 m₂ v_B^2 1 2 m₁ u₁^2 = 1 2 2 m ( 4 3 )^2 u^2 1 2 4 m u^2 & aligned Fraction of energy lost =8 / 9