A constant force of F=(i-2j-3k) causes a displacement d=(2i-5j+k), what will be the net workdone if f is in N and displacement is in meters?
Correct answer: B. 9 J
- A. 15 J
- B. 9 J
- C. 8 J
- D. 18 J
Explanation
Work done= force x distance(i-2j-3k)(2i-5j+k) multiply the coefficients of i then j then k and add them. (1x2) + (-2x-5) + (-3x1) w.d= 2+10+(-3) = 9 J
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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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