An object with a mass of 5 kg5kg is hanging from an axle with a radius of 21 cm21cm. If the wheel attached to the axle has a radius of 14 cm14cm, how much work would it take to turn the wheel 25 cm25cm?

1 Answer
Dec 28, 2017

The work done is =18.375J=18.375J

Explanation:

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The load is L=5gNL=5gN

The radius of the axle is r=0.21mr=0.21m

The radius of the wheel is R=0.14mR=0.14m

The effort is =FN=FN

The acceleration due to gravity is g=9.8ms^-2g=9.8ms2

Taking moments about the center of the axle

F*0.14=5g*0.21F0.14=5g0.21

F=(5g*0.21)/0.14=73.5NF=5g0.210.14=73.5N

The force is F=73.5NF=73.5N

The distance is d=0.25md=0.25m

The work done is

W=F*d=73.5*0.25=18.375JW=Fd=73.50.25=18.375J