Force acts for 20 s on a body of mass 20 kg, starting from rest, after which the force ceases and then the body describes 50 m in the next 10 s. The value of force will be:
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Force acts for 20 s on a body of mass 20 kg, starting from rest, after which the force ceases and then the body describes 50 m in the next 10 s. The value of force will be:

G1 Physics · Accepted Answer

After the force ceases, speed remains constant. Since the body covers 50 m in 10 s, v = 5 m s⁻¹. During the first 20 s, v = at gives a = 5/20 = 0.25 m s⁻². Therefore F = ma = 20 × 0.25 = 5 N.