A gardener pushes a lawn roller throughh a distance of 20m. He applies a force of 20kg weight in a direction inclined at 600
to the ground , find the work done by him.
Force applied, F = 20 kg weight = 20 × 9.8 = 198 N
The force is applied at an angle 60o with the ground. So, the component of the force that is responsible for displacement of the lawn mower is = F cos60 = 198 × 0.5 = 99 N
Now, work done = 99 × 20 = 1980 J