An object falls from a height of 10 m. After impacting the ground it loses 50% of its kinetic energy. To what height will it rebound?
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An object falls from a height of 10 m. After impacting the ground it loses 50% of its kinetic energy. To what height will it rebound?

G1 Physics · Accepted Answer

Step 1 — Principle: For motion under gravity without resistance, total mechanical energy K + U remains constant. Step 2 — Working: Before impact K=mgh=mg×10. Step 3 — Working: After impact half remains, K′=.5mg×10=mg×5. Step 4 — Working: At rebound apex this becomes mg h′, so h′=5 m. Correct answer: D — 5 m.