Answer:
Step-by-step explanation:
1 )
mass of earth M = 6 x 10²⁴ kg
mass of moon m = 7.35 x 10²² kg
distance d = 3.84 x 10⁸ m
force of gravity between earth and moon
F= GMm / d²
= 6.67 x 10⁻¹¹ x 6 x 10²⁴ x 7.35 x 10²² / (3.84 x 10⁸ )²
= 19.95 x 10¹⁹ N .
2 )
F= GMm / d²
1.76 x 10⁻⁸ = 6.67 x 10⁻¹¹ x m² / .45²
m² = .0534 x 10³
m = 7.30 kg
3 )
F= GMm / d²
8.7 x 10¹⁰ = (6.6 x 10⁻¹¹ x 6.39 x 10²³ x 6 x 10²⁴) / d²
d² = 29.085 x 10²⁶ m²
d = 5.39 x 10¹³ m .