Question 12
Work, Energy and PowerA box of mass 40 kg is being dragged along the floor by a rope inclined at 60° to the horizontal. The frictional force between the box and the floor is 100 N and the tension on the rope is 300 N. How much work is done in dragging the box through a distance of 4 m?
- A.680 J
- B.400 J
- C.200 J
- D.100 J
Show the answer and explanation
Answer: C (200 J)
Explanation
The forward pull is 300 cos 60° = 150 N. Taking away friction leaves a net force of 50 N, and 50 N × 4 m = 200 J.