Question

Calculate work done by gravity at at object of mass 19 kg at height of 80 km above earth surface

Answer 1

Given,

• Mass of object (M) = 19kg

• Height up to which the object is raised= 80 km

By the law "change in energy of the body gives the work done by the body"

Potential energy of body

P.E=Mgh

   =19×10×80×1000                       (1 KM=1000M)

    =152×10⁵  JOULE

Thus, change in potential energy is work done by the body. Here change in potential energy is 152×10⁵ JOULE  which is also the work done by body.