A body of mass m is taken from earth surface to the height h equal to twice the radius of earth Rₑ, the increase in potential energy will be : (g = acceleration due to gravity on the surface of Earth)
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Question

A body of mass m is taken from earth surface to the height h equal to twice the radius of earth Rₑ, the increase in potential energy will be : (g = acceleration due to gravity on the surface of Earth)

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G1 Physics · Accepted Answer

At Earth’s surface, Uᵢ = -GMm/Rₑ. At height h = 2Rₑ, distance from Earth’s centre is 3Rₑ, so Uᶠ = -GMm/(3Rₑ). Therefore ΔU = Uᶠ - Uᵢ = (2/3)GMm/Rₑ = (2/3)mgRₑ.