A body weighs 200N on the surface of the earth. How much will it weigh half way down to the center of the earth ?

Options

A. 100 N
B. 150 N
C. 200 N
D. 250 N

Answer

A

Explanation

Acceleration due to gravity at a depth d,
` g_d = g (1 -d/R)`
For d= R/2 `rArr g_d = g (1 - (R//2)/(R )) = g/2`
Required weight W. ` = mg_d = (mg)/(2) = W/2 = 200/2 = 100 N`