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.

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