A 0.5 kg ball falls from a height of 40 m and rebounds to 10 m. Find the magnitude of the impulse exerted by the ground. Take g = 9.8 m/s².
Physics · Mixed Chapter
NEET 2025

Question

A 0.5 kg ball falls from a height of 40 m and rebounds to 10 m. Find the magnitude of the impulse exerted by the ground. Take g = 9.8 m/s².

G1 Physics · Accepted Answer

Step 1: Take upward positive. Speed just before impact: v(initial) = −√(2gh₁) = −√(2 × 9.8 × 40) = −28 m/s. Step 2: Speed just after impact: v(final) = +√(2gh₂) = +√(2 × 9.8 × 10) = +14 m/s. Step 3: Impulse equals change in momentum: J = m(v(final) − v(initial)). Step 4: J = 0.5[14 − (−28)] = 0.5 × 42 = 21 N·s. Final answer: 21 N·s, Option A.