A stone is tied to a string of length ' l ' and is whirled in a vertical circle with the other end of the string as the centre. At a certain instant of time, the stone is at its lowest posit

Question

A stone is tied to a string of length ' l ' and is whirled in a vertical circle with the other end of the string as the centre. At a certain instant of time, the stone is at its lowest position and has a speed ' u '. The magnitude of change in velocity as it reaches a position where the string is horizontal ( g being acceleration due to gravity)is:NEET 2004

TestHub · Accepted Answer

According to the question Total energy at A = Total energy at B ⇒ 2 1 ​ m u 2 = 2 1 ​ m v 2 + m g l ⇒ v 2 = u 2 − 2 g l ​ ​ ∴ Change in magnitude of velocity = u 2 + v 2 ​ = 2 ( u 2 − g l ) ​

Physics - W.E.P. Question with Solution | TestHub

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