Assuming the earth to be a sphere of uniform mass density, a body weighed 300 ~N on the surface of earth. How much it would weigh at R/4 depth under surface of earth ?

Step-by-step solution

aligned & At surface: mg =300 ~N & ~m = 300 ~g _ s & At Depth R 4 : g _ d = g _ s [1- d R ] & g _ d = g _ s [1- R 4 R ] & g _ d = 3 ~g _ s 4 aligned weight at depth = m g _ d aligned & = m 3 ~g _ s 4 & = 3 4 300 & =225 ~N aligned