A railway carriage of mass 10000 kg moving with a speed of 15 ms–1 strikes a stationary carriages of the same collision, the carriages get coupled and move together. What is their common speed after collision?
Here, m₁ = 10000 kg, v₁ = 15 m/s, m₂ = 10000 kg, v₂ = 0, v = ?
As the collision is perfectly inelastic, therefore,
(m₁ + m₂)v = m₁v₁ + m₂v₂
(10000 + 10000)v = 10000 × 15 + 0
v = (10000 × 15) / 20000 = 7.5 m/s