Same chapter4 marksDifficulty: Hard
A pump raises 500 kg of water through a height of 12 m in 20 s. Calculate the power of the pump. Take g = 10 m s−2.
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4 marksDifficulty: Hard
A ball of mass 0.5 kg is dropped from a height of 20 m. Calculate its kinetic energy just before it strikes the ground and its velocity at that instant. Take g = 10 m s−2 and ignore air resistance.
Original Khojo Papers practice question — not from a past board paper.
Answer
Kinetic energy 100 J and velocity 20 m s−1
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
All the potential energy mgh = 0.5 × 10 × 20 = 100 J is converted to kinetic energy. Then ½ × 0.5 × v2 = 100 gives v2 = 400 and v = 20 m s−1.
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