a string is wrapped around a cylinder of mass M and radius R. the string is pulled vertically upwards to present the centre of mass from falling as the cylinder unwinds the string. find the tension in the string ?

Question

a string is wrapped around a cylinder of mass M and radius R. the string is pulled vertically upwards to present the centre of mass from falling as the cylinder unwinds the string. find  the tension in the string ?

anonymous · Answer

i mean this part:
the string is pulled vertically upwards to present the centre of mass from falling as the cylinder unwinds the string. find the tension in the string ?

anonymous · Answer

well acc. to my p view i think it means when the cylinder i winded with wire it centre of mass i founded where the weight is max. when we started unwinding without diturbing sytem how much tension we have to give to string o that the centre of mass dont get disturb

anonymous · Answer

Take the moment about the centre of the cylinder to be zero  or equate the two moments.
due to the tensile force and other due to the half of the weight that is Mg/2 acting downwards at the other coner,which gives( t=mg/2)

aravindg · Answer

its Mg

aravindg · Answer

You see the tension must exactly balance the weight of the cylinder,if the cylinder is not allowed to fall
Thus T=mg

aravindg · Answer

@heena its not "present" its "prevent" lol!!

anonymous · Answer

@arvind i typed the ques as in paper it was print not my fault :P

anonymous · Answer

but ans is Mg/3

aravindg · Answer

wat???

anonymous · Answer

hey heena can u please draw the diagram for this question? showing the strings section attached to the cylinder is it longitudinal or parallel?

anonymous · Answer

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