Gravity

Let's prove Gravitational acceleration on earth's center equals to 0. Basically, we suppose that mass of every point of the earth are the same. Acceleration g at a surface point is $g=\frac{G.M}{R^2}=G \times \rho\frac{4}{3}\pi\frac{R^3}{R^2}=\frac{4}{3}\pi\rho \times GR$ In the similar way, we have at an underground point: $g'=\frac{4}{3}\pi\rho \times G(R-h)$ . h is distance from surface to the point here. So, $\frac{g'}{g}=\frac{R-h}{R}$ or $g'=g\frac{R-h}{R}$ . In this problem, $h=R$ and $g'=0$ . However, we can guess easily the answer. :D

gravity is 0 on center of earth

seriously, i just think the man died when he reaches the center of the earth. he become ashes

g=0 at the center of earth and weight W=mg=0 of any object

Gravitational forces cancel out.

factual one.

since weight=mass gravity therefore weight at the center of the earth=4.08163265306 0=0