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प्रश्न
A coolie carrying a load on his head and moving on a frictionless horizontal platform does no work. Explain the reason why.
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उत्तर
We know W = F d cos θ.
Since force is normal to displacement.
So θ = 90°
Hence work done W = Fd cos θ 90 = 0.
संबंधित प्रश्न
A boy weighing 40 kgf climbs up a stair of 30 steps each 20 cm high in 4 minutes and a girl weighing 30 kgf does the same in 3 minutes. Compare:
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(Hint: The body is acted upon by the centripetal force.)
Name the force needed for circular motion. What is the direction of the force?
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