Q. Assuming earth to be a sphere of a uniform density, what is the value of gravitational acceleration in a min $100\ km$ below the earth’ surface (Given $R = 6400\ km$)
A) $9.66\ m/s^{2}$
B) $7.64\ m/s^{2}$
C) $5.06\ m/s^{2}$
D) $3.10\ m/s^{2}$
Explanation
(a) $g^{'} = g\left( 1 - \frac{d}{R} \right) = 9.8\left( 1 - \frac{100}{6400} \right) = 9.66m/s^{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.