An asteroid has a mass of 7*10^20 kg and a radius of 500 km. Determine?

Question

Determine
a) gravitational field strength
b) how much would 85 kg astranout weigh on the asteroid.

Answer 1

F = GmM/R^2; so g = GM/R^2; where R = 500,000 m and M = 7 X 10^kg. G = 6.67 X 10^-11 in kg-m-sec units.

a) g is a measure of the field strength.
b) W = mg the weight of the astronaut; where m = 85 kg and g is from a)

You can do the math.