Experiment 4 — The Recoiling Cannon

Topic: Physics · Class 9 · Momentum and its conservation; third law

Aim: Keep the cannon’s recoil speed below 1 m/s while still firing the 4 kg ball at 30 m/s.

Daily: A rifle kicks back into the shoulder, a garden sprinkler spins, a balloon shoots across the room when released, and a rocket rises — all the same conservation law.

Question: A heavier cannon firing the same ball at the same speed will recoil…

Exp: The same momentum divided by a larger mass gives a smaller velocity.

Question: Total momentum is conserved when…

Exp: That is the condition for conservation.

Question: A 2 kg ball at 10 m/s fired from a 20 kg cannon gives a recoil of…

Exp: 20 kg m/s ÷ 20 kg = 1 m/s.

Exp: It works in vacuum too — no air is needed.