21somebody try n help.....
1.217.
Find the proper potential energy of gravitational interaction of matter forming a 1)thin uniform spherical layer of mass m and radius R 2)uniform sphere of mass m and radius R
(i have done the 2nd part,need help in the 1st one
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2 Answers
1same concept applied as in electrostatics
suppose a mass m is of a shell of radius r
therefroe potnetial =-GM/r
thereofre work done in assembling a charge dm=change in potenital enrgy
w=-GMdm/R
therefore total work done =-GM^2/2R by an external force can anyone pls confirm that my sign is right