A child pulls a sled along a rough horizontal surface by applying a constant 20 N force at an angle 60 o above the horizontal. How much work does the child do, in Joules, by pulling the sled 15 meters?

150 J

Explanation:

Work done: This can be defined as the product of force and the horizontal distance moved along the direction of force. The S. I unit of Work is Joules. (J).

The expression for work is given as,

W = Fcos∅y ... Equation 1

Where W = Work done, F = Force, ∅ = Angle above the horizontal, y = distance.

Given: F = 20 N, ∅ = 60°, y = 15 meters.

Substitute into equation 1

W = 20 (cos60) * 15

W = 20 (0.5) * 15

W = 10*15

W = 150 J.

Hence the work done is 150 J.