A body weighs 200 N on the surface of the earth. How much will it weigh half way down to the centre of the earth [2019]
(1)
Acceleration due to gravity at a depth d,
gd=g(1-dR)
For d=R2⇒gd=g(1-R/2R)=g2
Required weight W'=mgd=mg2=W2=2002=100 N