23how is friction doing work wen the wheels are purely rolling ???? [7]
Two wheels of same masses M and radii R are joined coaxially so that the system can perform rolling motion on the ground.The system is released from the top of the inclined plane of inclination theta and height H.The system performs rolling motion on the inclined plane without slipping.The friction coefficient between the wheels and the inclined plane is mu.After some time the system reaches the bottom.Find the value of H for which the work done by the frictional force due to the inclined plane on the system is minimum during the complete motion.
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8 Answers
11@vinay work done 6Mgh/7 hai.
now what can we conclude about the minimum value of H
(kaha se liya hai yeh question)
23
1Friction offcourse does work by providing torque (to increase the angular velocity of the wheel)
I got work done as 4Mgh/7
I don't know how we can find max or min. from this. The question seems wrong.
23u fogot the translational part ?
mgsinθ - f = ma
fR = mR2α
so f = mgsinθ2
Wf = ∫ f R dβ - f y
= f (Rβ - y )
β = angle rotated by wheel
y = distance moved by com of wheel
so Rβ = y
hence Wf = 0
i didnt understand why the question mentions pure rolling and gives μ also
1hmm....if that is the case then the question might be asking about rolling friction...which is not in the syllabus of JEE (as far as I know)
21i also got the answer zero///
@qwerty ; i think pure rolling is important to findout the value of frictional force///but mu is not required//
