According to the question Total energy at A= Total energy at B 
⇒21mu2=21mv2+mgl⇒v2=u2−2gl ∴ Change in magnitude of velocity =u2+v2=2(u2−gl)
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:
Held on 30 Apr 2004 · Verified 9 Jul 2026.
2(u2−gl)
u2−gl
u−u2−2gl
2gl
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A bullet of mass 10 g moving with 400 m/s penetrates a wall and comes to rest. The loss in kinetic energy is:
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Work through every NEET UG Mechanics PYQ, year by year.