1.

A mass m is raised from the surface of earth to a point which is at a height nR from the surface of earth. Change in potential energyis :

Answer»

nmgR
`(2mgR)/(H)`
`(n)/(n+1)` (MGR)
`(mgR)/(n)`

Solution :Change in p.E `=(-GMM)/(R+nR)-((-GMm)/(R ))`
`=(GMm)/(R )-(GMm)/(R(n+1))=(GMm)/(R ) [1-(1)/(n+1)]`
`=(GMm)/(R )[(n+1-1)/(n+1)]=(gR^(2)m)/(R )[(n)/(n+1)]`
`=(n)/(n+1)mgR`
So the correct choice is (c ).


Discussion

No Comment Found

Related InterviewSolutions