Question

A gardener pushes a lawn roller to a distance of 20m. If he applies a force of 20kg weight in a direction inclined at an angle of 60° to the ground,find the work done(take g=9.8m/s^2)

Answer 1

Here is the answer, that is 1960J

Answer 2

Answer:

Work done = 1960 J

Explanation:

As given in question,

Distance travelled by the roller, d = 20 m

Applied force on the roller,F = 20 kg weight

                                               = 20 x 9.8 N

                                               = 196 N

Angle between ground and the force is 60°.

And as we know the work done on a system can be given by the dot product of applied force and distance travelled by the body.

Hence, in this case the work done can be given by

W = F.d

    $=\ Fdcos\theta$

    $=\ 196\times 20\times cos60^o$

    = 1960 J

Hence, the work done by the gardener is 1960 J.