AP EAMCET · PHYSICS · Work Power Energy
A girl of mass \(50 \mathrm{~kg}\) swinging on a cradle. If she moves with a velocity of \(2 \mathrm{~ms}^{-1}\) upwards in a direction making an angle \(60^{\circ}\) with the vertical, then the power generated is \(\left(\mathrm{g}=9.8 \mathrm{~ms}^{-2}\right)\)
- A \(245 \mathrm{~W}\)
- B \(490 \sqrt{2} \mathrm{~W}\)
- C \(490 \sqrt{3} \mathrm{~W}\)
- D \(980 \mathrm{~W}\)
Answer & Solution
Correct Answer
(C) \(490 \sqrt{3} \mathrm{~W}\)
Step-by-step Solution
Detailed explanation
\(\begin{aligned} & P=\vec{F} \cdot \vec{V} \quad=m g v \cos 150^{\circ} \\ & =50 \times 9.8 \times 2 \cos 150^{\circ} \quad=-490 \sqrt{3} \mathrm{w} \\ & P=490 \sqrt{3} \mathrm{watt}\end{aligned}\)
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