Nikee

A 182 cm tall man is digging a hole in the ground. He stops for a moment and says: "I am done with one quarter of the hole. When I finish the job the top of my head is going to be three times as far under the ground as far it is above the ground now." How...

Pretty sure the previous answer is incorrect, as the man's head wouldn't be three times as far under the ground as far it is above the ground now.

Using gravitational law, F = G(m1)(m2)/r^2, where m1 is the mass of the earth = 5.9742x10^24kg, m2= mass of the man = 900/9.81 = 91.74kg, the r is the distance between the man and the center of the air and it is equal to (6378km+9000m = 6387km), this comp...