At what angle the work done will be half of its maximum value:
Correct answer: D. 60°
- A. 0°
- B. 45°
- C. 30°
- D. 60°
Explanation
Work done by a force is calculated as W = Fdcosθ, where θ is the angle between the force and the direction of displacement. The work is maximum when cosθ is 1, which occurs at θ = 0°. To find when the work done is half of its maximum value, we need cosθ = 1/2, which occurs at θ = 60°. Therefore, the correct answer is 60°.The other options are incorrect because:At 0°, the work is maximum, not half.At 45°, the work is approximately 70.7% of the maximum.At 30°, the work is about 86.6% of the maximum.
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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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