Question

A gardener pushes a lawn roller through a distance of 20m if he applies a force of 20kg weight in a direction inclined at 70 degree to ground find the work done by himG=9.8m/s^2

Answer 1

The total force applied to the roller can be obtained as,

`\begin{gathered} F=(20\text{ kg-wt)(}\frac{9.8\text{ N}}{1\text{ kg-wt}}) \\ =196\text{ N} \end{gathered}`

The work done by the gardner can be given as,

`W=Fd\cos \theta`

Substitute the known values,

`\begin{gathered} W=(196N)(20m)(\frac{1\text{ J}}{1\text{ Nm}})cos70^(\circ) \\ =(3920\text{ J)(}0.342) \\ =1340.64\text{ J} \end{gathered}`

Thus, the work done by the gardener is 1340.64 J.