A force of 50 N pulls a box 4 m along the floor at 60 degrees to the horizontal. The work done is
Correct answer: B. 100 J
- A. 200 J
- B. 100 J
- C. 173 J
- D. 0 J
Explanation
Only the component of force along the displacement counts, so the work is 50 multiplied by 4 multiplied by cos 60, which is 200 multiplied by 0.5, giving 100 J. Ignoring the angle gives the 200 J distractor and using sin instead of cos gives 173 J. Work is a scalar, so the answer carries no direction.
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About Work
Work is done when a force produces displacement, with its value determined by the component of force along the displacement. The topic covers positive, negative and zero work, work by variable forces from force-displacement graphs, and the connection between net work and change in kinetic energy.
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