A metal ball of mass 2 kg moving with speed of 36 km h^(-1) has a head on collision with a stationary ball of mass 3 kg. If after collision, both the balls move together, then the loss in kinetic energy due to collision is

A metal ball of mass 2 kg moving with speed of 36 km h^(-1) has a head

1.	A metal ball of mass 2 kg moving with speed of 36 km h^(-1) has a head on collision with a stationary ball of mass 3 kg. If after collision, both the balls move together, then the loss in kinetic energy due to collision is
Answer» 40 J 60J 100 J 140 J Solution :Applying principle of conservation of linear momentum , `m_1 u_1 + m_2u_2 = (m_1 + m_2) v` `2 xx 10 + 3 xx 0 = (2 + 3) v :. v = 4 ms^(-1)` Initial KE, `K_1 = 1/2 m_1u_1^2 = 1/2 xx 2 xx 10^2 = 100 J` Final KE, `K_2 = 1/2 (m_1 + m_2) v^2 = 1/2 (2 + 3) xx 4^2 = 40 J` `:. ` Loss in KE = `K_1 - K_2 = 100 - 40 = 60 J`.