An object of mass 1 g is whirled in a horizontal circle of radius 0.5m at a constant speed of 2m/s. The work done on the object during one revolution is:
Correct answer: A. 0 J
- A. 0 J
- B. 2 J
- C. 1 J
- D. 4 J
Explanation
W = F .d W = Fcd cos0 = Fcd cos90o = Fd (0) = 0 Due to centripetal force the object will move in a circular path. In the circular path. the centripetal force "Fc" is perpendicular to velocity "v". As the, displacement "d" is parallel to the velocity "v". So the angle between the displacement "d" and the centripetal force "Fc" is 90o.
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About Work and Energy
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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