Question

Mass of the earth has been determined through

• A. Use of Kepler’s $\frac{T^{2}}{R^{3}}$constancy law
• B. Sampling the density of earth’s crust and using earth’s radius
• C. Cavendish’s determination of G and using earth’s radius and at its surface
• D. Use of periods of satellites at different heights above earth’s surface

Answer 1

Answer: (C)

Cavendish’s determination of G and using earth’s radius and at its surface

Answer 2

$g = \frac{GM_{E}}{R_{E}^{2}}orM_{E} = \frac{gR_{E}^{2}}{G}$

Cavendish determined the value of G.