What is the force of gravity at different distances from the center of Earth?

AI Thread Summary
The discussion focuses on calculating the force of gravity at different distances from the Earth's center, starting with a known force of 750N. The equation F=mg is initially mentioned, but it is clarified that the correct approach is to use F=G*m1*m2/distance^2. The gravitational constant G is noted, but it's pointed out that it is not necessary for this specific problem since the mass of the Earth is not provided. The conversation emphasizes understanding the relationship between gravitational force and distance, highlighting that as distance increases, the force decreases according to the inverse square law. Overall, the key takeaway is the importance of using the correct gravitational formula for varying distances.
soulja101
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Homework Statement


The force of gravity experienced by a person on Earth is 750N. What is the force of gravity on the same person aat each of the following distances, in multiples of the Earth's radius from the centre of earth?


Homework Equations



FG=mg

The Attempt at a Solution


The answers are A)3 B)10 C)22
750N/9.8N/kg
=76.53
 
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If you want to find the force of gravity at different distances use the equation-
F=G* mass1*mass2/distance^2

G=gravitational constant or 6.67*10^-11
masses in kilograms
distance in meters
the final force in Newtons
 
hover said:
If you want to find the force of gravity at different distances use the equation-
F=G* mass1*mass2/distance^2

hover:
The universal gravitational constant is not needed to answer this question. (Besides, you didn't give the mass of the Earth.)

Soulja:
Using F=mg is not correct; hover's equation is correct.

You know the force at one Earth radius. Using F = \frac{G m_1 m_2}{r^2}, can you determine the relation between the forces if the masses remain constant but the distance is varied?
 
sorry, my bad:blushing:
 
Last edited:
Nothing to apologize about. You provided the governing equation.
 

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