The gravitational acceleration g

AI Thread Summary
The discussion focuses on the relationship between Newton's law of gravitation and gravitational acceleration, g. It explains that g can be derived from the equation F=GMm/r^2 by substituting the mass and radius of the Earth, leading to the commonly accepted value of 9.8 m/s². The conversation emphasizes that while g is exactly 9.8 m/s² at one specific point, it remains approximately constant for practical purposes due to minimal variations in Earth's radius. Additionally, it highlights the connection between gravitational force and acceleration by equating Newton's laws. Overall, the thread illustrates how gravitational acceleration is calculated using fundamental physical constants.
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Suppose a particle of mass M is under gravitational attraction. The Newton's law of gravitation says that F=GMm/r^2, and the part Gm/r^2 is g (acceleration due to gravity how?)
 
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Why don't you look up the mass of the earth, the radius of the earth, and G and plug them into Gm/r^2 and see what you get? Is it close to the usual value of g?
 
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GMm/R2

Usually

M = mass of planet
m = mass of object/particle

but Newton also says..

F = mg

You can do the rest.
 
manimaran1605 said:
Suppose a particle of mass M is under gravitational attraction. The Newton's law of gravitation says that F=GMm/r^2, and the part Gm/r^2 is g (acceleration due to gravity how?)
At the surface of the earth, Gm/r^2= g using m= mass of the earth, r= radius of the earth.
 
At only one point is GM/r^2 exactly equal to 9.8. However, since r only changes slightly with respect to its value at heights we experience, for all intents and purposes, g=9.8m/s^2.
 
manimaran1605 said:
Suppose a particle of mass M is under gravitational attraction. The Newton's law of gravitation says that F=GMm/r^2, and the part Gm/r^2 is g (acceleration due to gravity how?)

Like noted above, you get it by equating Newton's gravity law with Newton's second law.
You can plug in some numbers here: Earth's Gravity.
 
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