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 35 cm35cm, how much work would it take to turn the wheel a length equal to the circumference of the axle?

1 Answer
Apr 25, 2017

The work is =77J=77J

Explanation:

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The load L=(7g)N#

Radius of axle r=0.25mr=0.25m

Radius of wheel R=0.35mR=0.35m

Taking moments about the center of the axle

F*R=L*rFR=Lr

F*0.35=7*g*0.25F0.35=7g0.25

F=(7*g*0.25)/0.35=49NF=7g0.250.35=49N

Distance is d=2pir=2*pi*0.25=(0.5pi)md=2πr=2π0.25=(0.5π)m

Work is W=Fd=49*0.5pi=77JW=Fd=490.5π=77J