A man pulls a sled along a rough horizontal surface by applying a constant force at an angle $\theta$above the horizontal. In pulling the sled a horizontal distance d, the work done by the man is:

Question

A man pulls a sled along a rough horizontal surface by applying a constant force  at an angle $\theta$above the horizontal. In pulling the sled a horizontal distance d, the work done by the man is:

Quizplus · Accepted Answer

The work done by the man is given by the dot product of the force and the displacement. Since the force is at an angle to the horizontal, we need to use the component of the force that is in the same direction as the displacement. This is given by F cos F1F1F1S1F1F1F10. Thus, the work done is W = Fd cos F1F1F1S1F1F1F10. Choice B is the correct answer.

A Man Pulls a Sled Along a Rough Horizontal Surface θ\thetaθ

A Man Pulls a Sled Along a Rough Horizontal Surface $\theta$