Physics Question - Gravitational Forces

Question

1. Two spherical balls are placed so their centers are 255 cm apart. The force between the two balls is... 2.80 x 10-12 N. What is the mass of each ball if one ball is 3.00 kg more than the mass of the other ball?

Answer 1

I will set this up for you to where there is one equation in one unknown, and then you take it from there.

F = GMm/d²

Mm = Fd²/G

M = m + 3.0 kg

(m + 3)m = Fd²/G

In this last equation, plug in the values:

F = 2.80 x 10^-12 N

d = 2.55 meters

G = 6.67 x 10^-11 Nm²/kg²

That leaves you with a single equation in m. Solve for m, then get m + 3. The answers will be in units of kg. You should be able to finish from here.