The recoil speed of the cannon is 3 m/s.
Explanation:
Law of conservation of momentum is used to find the recoil speed of the cannon.
m₁v₁ = -m₂v₂
m₁= mass of clown = 100 kg
v₁ = speed of the clown = 15 m/s
m₂= mass of the cannon = 500 kg
v₂ = speed of the cannon = ?
Plugin the values, we will get,
v₂ = m₁v₁ / -m₂ = -100×15/ 500 = -1500 / 500 = 3 m/s
So the recoil speed of the cannon is 3 m/s.