IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: XaM!! on May 02, 2010, 10:35:52 am
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Two particles P and Q have mass 0.5 kg and m kg respectively, where m < 0.5. The particles are connected by a light inextensible string which passes over a smooth, fixed pulley. Initially P is 3.15 m above horizontal ground. The particles are released from rest
When P strikes the ground, P does not rebound and the string becomes slack. Particle Q then moves freely under gravity, without reaching the pulley, until the string becomes taut again.
e) Find the time between the instant when P strikes the ground and the instant when the string becomes taut again.
I got 6/7 s which is the right answer
But I was thinking when P hits the ground doesn't Q move up 3.15m and so i calculate the time for this and add it on to the time for the string going slack
I've attached the question picture
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No cos the acceleration is not the same - anyway it says from when P hits the ground