(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A mass 4m lying on a rough horizontal table is connected by a string,

passing over a pulley, to another mass 3 m hanging freely. The pulley (regarded

as a disk) has mass 4 m and rotates freely about a polar axis parallel to the

edge of the table. The coefficient of kinetic friction between the mass and the

table is μ=3/8. Assuming that the string does not slip on the pulley, Find the

common acceleration of the masses and show that the ratio of the tensions in

the string on either side of the pulley is T1 : T2 = 13 : 15. (You may assume

that the moment of inertia of a disk of radius r and mass m about a polar axis

through the disk is I =1/2 M r^2)

[D] Attempt

acceleration

4mg-t=4a

t-3mg=3A

1g=7a

10=7a

a=10/7

a=1.428

Tension 2:

4m(g)=4m(10)=40m

3/8=T2/40 , 120/8 = T2 , T2=15m

Tension 1:

3(10)=30

am i on the right track?

Thanks for the help have a big exam and this is a common question , having problems with it because the pulley is moving and dont know how it effects the acceleration .solution would be fantastic !!:shy:

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# Homework Help: Mechanics Pulley question !

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