Universal gravitation - radius?

In summary, the formula for universal gravitation is F = G * (m1 * m2)/r^2, where F is the force of gravity, G is the gravitational constant, m1 and m2 are the masses of the two objects, and r is the distance between the two objects. The force of gravity is inversely proportional to the square of the distance between two objects, meaning that as the radius increases, the force of gravity decreases. The radius also has a direct relationship with the gravitational pull, meaning that as the radius increases, the gravitational pull decreases. In terms of orbital speed, the radius has an inverse relationship, so as the radius increases, the orbital speed decreases. Additionally, the radius of an object can
  • #1
Mirole
33
0
Using F = G * (m1*m2)/(r2)

We know that

G = 6.6673x10-11 N*m2/kg2
m1(earth) = 6x1024 kg
m2(moon) = 7.4x1022 kg
the Earth and moon are an average of 3.9x108m apart

would r2 be [3.9x108]2 or [3.9x108 / 2]2?

-Thanks!
 
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  • #2
Why would you divide the distance in half?
 
  • #3
Here we are using radius...!
So, the first one is correct.

Here the distance between the two bodies mean the distances from their centres.
So, definitely, they are mentioning the radius
 

FAQ: Universal gravitation - radius?

1. What is the formula for universal gravitation?

The formula for universal gravitation is F = G * (m1 * m2)/r^2, where F is the force of gravity, G is the gravitational constant, m1 and m2 are the masses of the two objects, and r is the distance between the two objects.

2. How does the radius affect the force of gravity?

The force of gravity is inversely proportional to the square of the distance between two objects. This means that as the radius increases, the force of gravity decreases. In other words, the farther apart two objects are, the weaker the force of gravity between them.

3. What is the relationship between the radius and the gravitational pull?

The radius has a direct relationship with the gravitational pull. As the radius increases, the gravitational pull decreases. This is because the farther apart two objects are, the weaker the force of attraction between them.

4. How does the radius affect the orbital speed of an object?

The radius has an inverse relationship with the orbital speed of an object. As the radius increases, the orbital speed decreases. This is because the farther an object is from the center of mass, the slower it moves due to the weaker gravitational pull.

5. Can the radius of an object affect its gravitational field?

Yes, the radius of an object can affect its gravitational field. The larger the radius, the larger the gravitational field. This is because a larger radius means a larger surface area for the force of gravity to act upon, resulting in a stronger gravitational field.

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