Gravitational Force Calculator

Enter the mass of object 1, the mass of object 2, and the distance between them and this calculate will evaluate the gravitational force between them.

What is gravitational force?

Gravitational force is governed by on of Newton’s laws, specifically his universal gravitation law that says that every body attracts very other body with a force. This force is gravity. It’s one of the most bizarre forces in our universe. You may be sitting there thinking, i’m not getting pulled apart in every direction by things around me, and objects are just flying towards me. This is true, but that’s because the gravitational force is extremely weak. Only at very large masses does the force amount to something. For example, with the earth. The force of gravity due to the mass of the earth causes a gravitational potential energy.

Gravitational Force Formula

The gravitational force between two objects is calculated with the following formula:

F = G * M * m / R^2

  • Where F is the gravitational force.
  • M is the mass of the larger object
  • m is the mass of the smaller object
  • R is the distance between the center of the objects
  • G is the gravitation constant which is equal to 6.674*10^-11 N*m^2/k^2

How to calculate gravitational force

The following example shows how someone might calculate the gravitational force between two circular objects that have their center of masses exactly in the center of their body.

How to calculate gravitational force

  1. First, determine the mass of the larger object

    In many cases, the larger object is a body like a planet or celestial body. In this case the mass will need to be calculated using known physics of gravity. For the most part, you can just look up the mass of any planet in the solar system. For this example we will assume the object is the earth, which has a mass of 5.972 × 10^24 kg.

  2. Next, weight or measure the mass of the smaller object

    For this example we are going to use a bowling ball as our smaller object. We will say that we put the ball on a scale in found the mass to be 10kg.

  3. Next, measure the radius of the distance between objects.

    Since we are using the earth as the larger object, we can simply take the radius of the earth, add it to the height the bowling ball is placed at, then finally add the radius of the bowling ball. For this example we will assume this ads up to 6.379 km.

  4. Finally, enter all of the known information into the formula

    We now have all of the information needed to perform out calculation. We enter all of the information and find the force due to gravity to be approximately 98N.

  5. Analyze the results

    Check the answer to make sure it makes logical sense and apply what you learned to other problems.

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