Question

A body of mass 1 kg is rotating in a circular path of radius 1 m with constant velocity of 5 rev/sec. The work done in one complete revolution is​

Answer 1

Answer:

in one complete revolution displacement is zero so work done is zero.

Answer 2

Given:

A body of mass 1 kg is rotating in a circular path of radius 1 m with constant velocity of 5 rev/sec.

To find:

Work done in one complete revolution.

Calculation:

Work done by a force causing a displacement of d is given as :

$\boxed{ \sf{work = | \vec{F}| \times | \vec{d}| \times \cos( \theta) }}$

Here $\theta$ is the angle between the force vector and displacement vector.

Now , in a circular trajectory the force victor is contributed by the centripetal force which is located at an angle of 90° to the displacement vector.

$= > \sf{work = | \vec{F}| \times | \vec{d}| \times \cos( {90}^{ \circ} ) }$

$= > \sf{work = | \vec{F}| \times | \vec{d}| \times0}$

$= > \sf{work = 0 \: joule}$

So, irrespective of the displacement travelled in a circular trajectory the work done will always be zero.

So, final answer is:

$\boxed{\bf{work = 0 \: joule}}$