An object with a mass of 2 kg2kg is hanging from an axle with a radius of 2 cm2cm. If the wheel attached to the axle has a radius of 8 cm8cm, how much work would it take to turn the wheel a length equal to the circumference of the axle?

1 Answer
Mar 23, 2018

The work =2.46J=2.46J

Explanation:

www.odicis.org

The load is L=2gNL=2gN

The radius of the axle is r=0.02mr=0.02m

The radius of the wheel is R=0.08mR=0.08m

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*0.08=2g*0.02F0.08=2g0.02

F=(2g*0.02)/0.08=4.9NF=2g0.020.08=4.9N

The force is F=4.9NF=4.9N

The distance is d=2piR=2pi*0.08=0.16pimd=2πR=2π0.08=0.16πm

The work done is

W=F*d=4.9*0.16pi=2.46JW=Fd=4.90.16π=2.46J