Question

Suppose a charge +q on Earth’s surface and another +q charge is placed on the surface of the Moon, (a) Calculate the value of q required to balance the gravitational attraction between Earth and Moon (b) Suppose the distance between the Moon and Earth is halved, would the charge q change? (Take m_E = 5.9 x 10²⁴ kg, m_M = 7.348 x 10²² kg)

Answer 1

Mass of the Earth, M_E = 5.9 x 10²⁴ kg 

Mass of the Moon, M_M = 7.348 x 10²² kg 

Charge placed on the surface of Earth and Moon = q 

(a) Required charge to balance the F between Earth and Moon

(b) The distance between Moon and Earth is

so q = 5.67 x 10¹³ C 

There is no change.