Step-by-step explanation:
(a)
F = (GM1M2)/r²
F = (6.7 X 10^-11 x 30.3 x 40.17)/0.5²
F = 326.197 x 10^-⁹N
(b)
F =750N
G = 6.7 x 10^-11
M1 = 2050kg
r = 70.3m
M2 = ?
F = (GM1M2)/r²
F x r² = GM1M2
(F x r²)/GM1 = M2
M2 = (750 x 70.3²)/(6.7 x 10^-11 x 2050)
M2 = 26.99kg