During a solar eclipse, the Moon, Earth, and Sun all lie on the same line, with the Moon between the Earth and the Sun.

(a) What force is exerted by the Sun on the Moon?
(b) What force is exerted by the Earth on the Moon?
(c) What force is exerted by the Sun on the Earth?

Respuesta :

Answer:

(a) [tex]F_{sm} = 4.327\times 10^{20}\ N[/tex]

(b) [tex]F_{em} = 1.983\times 10^{20}\ N[/tex]

(c) [tex]F_{se} = 3.521\times 10^{20}\ N[/tex]

Solution:

As per the question:

Mass of Earth, [tex]M_{e} = 5.972\times 10^{24}\ kg[/tex]

Mass of Moon, [tex]M_{m} = 7.34\times 10^{22}\ kg[/tex]

Mass of Sun, [tex]M_{s} = 1.989\times 10^{30}\ kg[/tex]

Distance between the earth and the moon, [tex]R_{em} = 3.84\times 10^{8}\ m[/tex]

Distance between the earth and the sun, [tex]R_{es} = 1.5\times 10^{11}\ m[/tex]

Distance between the sun and the moon, [tex]R_{sm} =  1.5\times 10^{11}\ m[/tex]

Now,

We know that the gravitational force between two bodies of mass m and m' separated by a distance 'r' is given y:

[tex]F_{G} = \frac{Gmm'_{2}}{r^{2}}[/tex]                             (1)

Now,

(a) The force exerted by the Sun on the Moon is given by eqn (1):

[tex]F_{sm} = \frac{GM_{s}M_{m}}{R_{sm}^{2}}[/tex]

[tex]F_{sm} = \frac{6.67\times 10^{- 11}\times 1.989\times 10^{30}\times 7.34\times 10^{22}}{(1.5\times 10^{11})^{2}}[/tex]

[tex]F_{sm} = 4.327\times 10^{20}\ N[/tex]

(b) The force exerted by the Earth on the Moon is given by eqn (1):

[tex]F_{em} = \frac{GM_{s}M_{m}}{R_{em}^{2}}[/tex]

[tex]F_{em} = \frac{6.67\times 10^{- 11}\times 5.972\times 10^{24}\times 7.34\times 10^{22}}{(3.84\times 10^{8})^{2}}[/tex]

[tex]F_{em} = 1.983\times 10^{20}\ N[/tex]

(c) The force exerted by the Sun on the Earth is given by eqn (1):

[tex]F_{se} = \frac{GM_{s}M_{m}}{R_{es}^{2}}[/tex]

[tex]F_{se} = \frac{6.67\times 10^{- 11}\times 1.989\times 10^{30}\times 5.972\times 10^{24}}{((1.5\times 10^{11}))^{2}}[/tex]

[tex]F_{se} = 3.521\times 10^{20}\ N[/tex]