Free Martian immigrants

(1) According to the displacement-time relation of free falling body h= 12gt2, there are:

g=2ht2

Solution: G 1G2 = T22 1 = 49.

(2) The velocity of the first universe is the velocity around the planet surface, and gravity is equal to the centripetal force. According to Newton's second law, there are:

mg=mv2R

Solution: v=gR

Therefore, v1v2 = g1r1g2r2 = 49×12 = 23.

A: (1) The ratio of gravity acceleration on the surface of Mars to that on the surface of the Earth is 49.

(2) The ratio of the minimum speed (v 1) of launching manned spacecraft on the surface of Mars to the minimum launching speed (v2) of satellites on Earth.