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Mechanics

a 70 kg man leans against a hollow cylindrical wall with radius 3m.coefficient of friction between clothing and wall is 0.15.find minimum speed of rotation of cylinder so that the man doesnt fall when the floor is removed?

Profile image of pk bose
13 Years agoGrade
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3 Answers

Profile image of rupali sehgal
ApprovedApproved Tutor Answer13 Years ago

Taking the man to be the system,

Normal force supplies the necessary centripetal force.

therefore, N=mv2/R

Also, to ensure that the person does not fall, frictional force should be equal to the person''s weight.

therefore, F= mg

=> µs.N=mg

from (1)

µs.mv2/R=mg

µs(Rω)2/R=g                 {v=Rω}

(0.15)(3)(ω)2 =10

ω2= 10/0.45= 22.22

ω = 4.71 rad/sec2

 

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Profile image of pk bose
13 Years ago

thanx a lot !! helped me a lot ! thank u!

Profile image of rupali sehgal
13 Years ago

Your welcome!