Question

A particle of mass 1 kg moves in a circular
path of radius 1m such that its speed varies
with time as per equation v = 3t2 m/s where
time t is in seconds. The power delivered by
the force acting on the particle at t = 1s, is :-
(a) 36 W
(b) 20 W
(c) 18 W
(d) Zero​

Answer 1

Answer:

Here Tangential acceleration takes place.

So tangential force = m*dv/dt = 1*6t = 6t

At t= 1, Tangential force = 6*1 = 6 Newton

So, Tangential power = F*v*cos(theta)

Here theta =0° , since angle between tangential force and tangential velocity is zero degree.

So, Tangential power = Force*velocity*cos(0°) = 6*3(1)^2 *1 = 18W

Explanation: