An object is displaced from point A (0, 1, 1) m to point B (1, 4, 3) m under a constant force F = (i + 2j + 3k). Find the work done by this force in this process:
Correct answer: A. 13 J
- A. 13 J
- B. 15 J
- C. 0 J
- D. 14 J
Explanation
Here, d = (1-0, 4-1, 3-1) and d = (1, 3, 2) We know that W = Fd cos θ = (1, 2, 3)(1, 3, 2) {all unit vectors will be canceled because unit vector * unit vector = 1} = (1*1 + 2*3 + 3*2) = 1 + 6 + 6 = 13 J Hence, option A is the correct option.
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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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