Question

The value of g(acceleration due to gravity) at earth's surface is $10$m$s^{-2}$. Its value in m$s^{-2}$ at the centre of the earth which is assumed to be a sphere of radius R metre and uniform mass density is?

• A. $5$
• B. $\frac{10}{R}$
• C. $\frac{10}{2R}$
• D. Zero

Answer 1

Answer: (D)

Zero

There is no mass at exact center of Earth to provide a gravitational pull and thus a gravitational acceleration$\Rightarrow$acceleration due to gravity $\frac{GM}{r^2}$ is $0$ at center

According to shell theorem-no outside mass provides gravitational pull at center of Earth.