Question

a ball of mass 2kg moving with a 36km/hr has a head on collision with a stationary ball of mass 3kg. If after collision both the balls move together then the loss in kinetic energy due to collision is

Answer 1

Final velocity = mu / (m + M)
= (2 × 36 × 5/18) / (2 + 3)
= 4 m/s

Loss in kinetic energy = Iniatial kinetic energy - Final kinetic energy
= 0.5mu² - 0.5(m + M)v²
= 0.5 × [(2 × (36 × 5/18)²) - (3 × 4²)]
= 76 J