Question

The earth exerts a gravitational pull of 2*10^20 N on the moon; the sun exerts a gravitational pull of 4.3*10^20 N on the moon. What is the net force on the moon when the angular separation between the earth and the sun is 90 as seen from the moon?

Answer 1

According to the rule of addition of vectors, the resulting force is $F = (f_1^{2} + f_2^{2})^{0.5} = (4 + 18.5)^{0.5}10^{20} = 4.7\cdot10^{20} N$