Understanding the Gravitational Constant Formula | Jamie

In summary, the formula being discussed is the Law of Universal Gravitation, which uses the constant G to calculate the force of gravity between two objects based on their masses and distance. G has units of m^3 kg^-1 s^-2 and was first measured by Henry Cavendish and later refined by C.V. Boys using different experimental setups.
  • #1
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Can someone explain the following formula to me? I would like to know what m, kg, and s are. At glance I believe this is the cross product of 6.67384 and the other half of the formula. However I am very unsure on how to continue into solving this for any specific value. I believe m is for the mass of a given object? A quick step by step solution of this formula would be helpful.

G = 6.67384 × 10^-11 m^3 kg^-1 s^-2

Thanks,
Jamie
 
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  • #2
m, kg and s are the units this constant is written in (meters, kilograms and seconds respectively).

The constant is read as 6.67384 times 10 to the power of -11 cubic meters per kilogram second squared.
 
  • #3
That's a constant, not a formula.

The formula is the Law of Universal Gravitation, by Sir Isaac Newton:

F_Gravity = G * (m1 * m2) / r^2

Where m1 and m2 are the masses and r is the distance between them.

For a planet orbiting a star or moon orbiting a planet, in a circular orbit r is the radius of the circle of the orbit, hence the use of "r" instead of "d" for distance.

The units for G can be found by working backwards from the formula:

[Newtons] = G * [kg * kg] / [m^2]

so G has units of kg^2 m^(-2) N^(-1) or m^3 kg^-1 s^-2

G is measured from experiments, just like other constants.
 
  • #4
Henry Cavendish first measured G by suspending 2 little masses on a torsion setup that were allowed to rotate. And then set another 2 larger masses on the outside and then let the thing come to equilibrium, and then he moved the larger masses and then measured the change in the angle. Knowing the resistance in the thread he was able to calculate G.
Later C.V. Boys modified the experiment and took 2 spheres and then set them on a balance and then put a larger sphere under one of the balance pans and the measured the deflection angle and was able to calculate G.
 
  • #5


Hello Jamie,

The formula you are referring to is the Gravitational Constant formula, which is used to calculate the gravitational force between two objects. The letters m, kg, and s stand for meters, kilograms, and seconds respectively. These are the units of measurement used in the formula to represent mass, distance, and time.

To understand the formula, let's break it down step by step:

1. G is the symbol for the Gravitational Constant, which is a fundamental constant in physics. It is a fixed value that represents the strength of the gravitational force between two objects.

2. The number 6.67384 is the numerical value of the Gravitational Constant, which has been measured and determined by scientists through experiments.

3. The ^-11 after 10 represents the negative exponent, which means the decimal point is moved 11 places to the left. This is because the Gravitational Constant is a very small number.

4. The units m^3 kg^-1 s^-2 represent the units of the Gravitational Constant, which are meters cubed per kilogram per second squared. This is a combination of the units for mass, distance, and time.

5. To use this formula, you would need to know the masses of the two objects (in kilograms) and the distance between them (in meters). You would then plug these values into the formula and solve for the gravitational force (in Newtons).

I hope this helps to clarify the formula for you. If you have any further questions, don't hesitate to ask. Keep exploring and learning!

Best,
 

Related to Understanding the Gravitational Constant Formula | Jamie

1. What is the gravitational constant formula?

The gravitational constant formula, denoted as G, is a mathematical equation that represents the strength of the gravitational force between two objects. It is a fundamental constant in physics and is used to calculate the force of gravity between any two objects in the universe.

2. How is the gravitational constant formula calculated?

The gravitational constant formula is calculated by measuring the gravitational force between two objects of known mass and distance and then solving for G using the equation F = (G x m1 x m2)/d^2, where F is the force of gravity, m1 and m2 are the masses of the two objects, and d is the distance between them.

3. What is the value of the gravitational constant?

The value of the gravitational constant is approximately 6.67 x 10^-11 m^3/kg*s^2. This value is a fundamental constant and does not change, regardless of the masses or distances between objects.

4. Why is the gravitational constant important?

The gravitational constant is important because it helps us understand the force of gravity between objects and how it affects the motion of celestial bodies in the universe. It also allows us to make accurate predictions about the behavior of objects under the influence of gravity.

5. How does the gravitational constant formula relate to Newton's law of universal gravitation?

The gravitational constant formula is a mathematical representation of Newton's law of universal gravitation, which states that the force of gravity between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. The gravitational constant acts as a proportionality constant in this equation.

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