A 2 kg metal ball travelling at 36 km h⁻¹ collides head-on with a stationary 3 kg ball and they stick. Find loss of kinetic energy.
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A 2 kg metal ball travelling at 36 km h⁻¹ collides head-on with a stationary 3 kg ball and they stick. Find loss of kinetic energy.

G1 Physics · Accepted Answer

Step 1 — Principle: Conserve momentum in a perfectly inelastic collision; objects share a common final velocity. Step 2 — Working: Initial speed 36 km/h=10 m/s. Step 3 — Working: Momentum conservation gives common speed V=(2×10)/5=4 m/s. Step 4 — Working: Ki=½×2×10²=100 J and Kf=½×5×4²=40 J. Step 5 — Working: Loss=60 J. Correct answer: D — 60 J.