g. The mass of the earth is 6 x 10^{24 }kg. The distance between the earth and the Sun is 1.5x 10^{11} m. If the gravitational force between the two is 3.5 x 10^{22} N, what is the mass of the Sun?

**the mass of the earth, m = 6 **× **10**²⁴ kg

**Assume the mass of the sun is M **

distance between earth and sun , r = 1.5 × **10**¹¹ **m**

**force between sun and earth , F = 3.5 **× **10**²² ** N
use gravitational force formula,
F = GMm/r**²

3.5 × 10²² = 6.67 × 10⁻¹¹ × 6 × 10²⁴ M/(1.5 × 10¹¹)²

3.5 × 10²² × 2.25 × 10²²/(6.67 × 6 × 10¹³) = M

M = 0.196 × 10³¹ kg

hence,