A 2 kg block is released from rest from a height of 0.9 m above a smooth horizontal surface. It then compresses an initially uncompressed spring of force constant 400 N/m. If the maximum compression is N/10 m, find N. Take g = 10 m/s².
Physics · Work , Power and Energy · conservation of mechanical energy
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Question

A 2 kg block is released from rest from a height of 0.9 m above a smooth horizontal surface. It then compresses an initially uncompressed spring of force constant 400 N/m. If the maximum compression is N/10 m, find N. Take g = 10 m/s².

Physics · Work , Power and Energy · conservation of mechanical energy

G1 Physics · Accepted Answer

Mechanical energy is conserved: mgh = ½kx². Thus 2×10×0.9 = ½×400×x² ⇒ 18=200x² ⇒ x²=0.09 ⇒ x=0.30 m=3/10 m. Hence N=3.