A body of mass 3 kg is under a constant force which causes a displacement s in metres in it, given by the relation s = (1/3)t², where t is in s. Work done by the force in 2 s is :

Question

Dr. Abubacker · Accepted Answer

[Solution from source] From s = t²/3, v = ds/dt = 2t/3 and a = 2/3 m s⁻², so the force is F = 3 × 2/3 = 2 N. At t = 2 s, s = 4/3 m, so W = 2 × 4/3 = 8/3 J; this equals the gain in kinetic energy ½ × 3 × (4/3)² = 8/3 J. The reciprocal 3/8 J is a slip in the algebra. Answer (3).

Q. A body of mass 3 kg is under a constant force which causes a displacement s in metres in it, given by the relation s = (1/3)t², where t is in s. Work done by the force in 2 s is :

Explanation

Reviewed by Dr. Abubacker

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