The gravitational field intensity at a height of 150 km above the surface of Uranus is 8.71 N/kg. The radius of Uranus is 2.56 x 107 m.

Question

a. Calculate the mass of Uranus.
b. Calculate the gravitational field intensity at the surface of Uranus.
c. How much would a 100 kg person weigh on the surface of Uranus?

Answer 1

g =8.71 N/kg.
h = 150 000 m=1.5•10^5 m
R= 8.71•10^7 m.

(a) g = G•M/(R+h)².
M = gR²/G,
where the gravitational constant G =6.67•10^-11 N•m²/kg²,
(b) gₒ = G•M/R².
(c) m•gₒ.