A 4 kg particle moves along the x-axis with velocity v = 2x m/s. The net force acting on it is F = 3x² N. At x = 2 m, the rate of increase of kinetic energy is N watt. Find N.
Physics · Work , Power and Energy · Power
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Question

A 4 kg particle moves along the x-axis with velocity v = 2x m/s. The net force acting on it is F = 3x² N. At x = 2 m, the rate of increase of kinetic energy is N watt. Find N.

G1 Physics · Accepted Answer

The rate of increase of kinetic energy equals net power: dK/dt=Fv. At x=2, F=12 N and v=4 m/s, so N=48.