As you go above the earth's surface, the acceleration due to gravity will decrease. find the height, in meters, above the earth's surface where this value will be 1/140 g.

Respuesta :

Gravitational force follows an inverse square law, so your distance will be
  √140 ≈ 11.832160
times the radius of the earth from the center of the earth, or 10.832160 times the radius of the earth above the surface.

That distance is about (6.371·10^6 m)·10.832160 ≈ 6.901·10^7 m.

Answer:

[tex]h = 2.36 X 10^{8}[/tex] m

Explanation:

An object kept in height h in space above the earth's surface is acted upon by force F which is given by;

F = [tex]\frac{GMm}{(R+h)^{2} }[/tex]

where F = mg

mg = [tex]\frac{GMm}{(R+h)^{2} }[/tex]

g = [tex]\frac{GM}{(R+h)^{2} }[/tex]

[tex](R+h)^{2} = \frac{GM}{g}[/tex]

M = Mass of earth = [tex]5.98 X 10^{24}[/tex] kg

R = Radius of earth =  [tex]6.38 X 10^{6}[/tex] m

G = Gravitational constant =  [tex]6.67259 X 10^{-11}[/tex] N[tex]m^{2}[/tex] /[tex]kg^{2}[/tex]

g = 1/140 g = [tex]7.14286 X 10^{-3}[/tex]

[tex]h^{2} = \frac{GM}{g} - R^{2}[/tex]

substituting for M, R, G and g

(Kindly ignore Armstrong symbol in the following equation, I don't know how it popped up using the equation tool)

[tex]h^{2}  = \frac{(6.67259X10^{-11}) X (5.98 X 10^{24} ) }{(7.14286 X 10^{-3}) }  - (6.38 X 10^{6}) ^{2}[/tex]

[tex]h^{2} = \frac{3.99 X 10^{14} }{7.14286 X 10^{-3} } - 4.07 X 10^{13}[/tex]

[tex]h^{2} = 5.586 X 10^{16} - 4.07 X 10^{13}[/tex]

[tex]h^{2} = 5.58193 X 10^{16}[/tex]

[tex]h = \sqrt{(5.58193 X 10^{16})}[/tex]

[tex]h = 2.36 X 10^{8}[/tex] m

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