An object with a mass of 7 kg7kg is hanging from an axle with a radius of 25 cm25cm. If the wheel attached to the axle has a radius of 75 cm75cm, how much work would it take to turn the wheel a length equal to the circumference of the axle?

1 Answer
Mar 29, 2017

The work done is =35.92J=35.92J

Explanation:

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The load =(7g)N=(7g)N

Radius of axle r=0.25mr=0.25m

Radius of wheel R=0.75mR=0.75m

Taking moments about the center of the axle

F*0.75=7*g*0.25F0.75=7g0.25

F=(7*g*0.25)/0.75=7/3g=22.87NF=7g0.250.75=73g=22.87N

The distance is =2*pi*0.25=0.5pi=2π0.25=0.5π

The work done is

W=F*d=22.87*0.5pi=35.92JW=Fd=22.870.5π=35.92J