ANL - Newton's Law of Universal Gravity

Newton's Law of Universal Gravity

All objects with mass exert a force on every other object with a mass. Newton's Law of Universal Gravitation states that the force between masses is directly proportional to the mass and inversely proportional to the square of the distance between them. On the Earth's surface the force between an object and the Earth is called weight. It is necessary to introduce the Universal Gravitational Constant to convert the proportionality to an equality. Please watch the following presentation that will introduce Newton's Law of Universal Gravitation.

Newton's Law of Universal Gravity Practice

Newton's Law of Universal Gravitation is just a way to determine the force between two objects that have a mass. Once the value of the force is calculated, it is treated like any other force. Please watch the following presentation of some example problems. 

Newton's Law of Universal Gravity Self-Assessment

Now it's your turn. Complete the following Gravitation problems to verify that you understand how to solve them.

  1. The mass Jupiter's moon Io is 8.94 x 1022 kg and its orbital radius around Jupiter is 421,600km. If the period of the orbit is 1.769 days, what is the mass of Jupiter? 

SOLUTION

  1. If the Earth were to be compressed like a black hole, it would be small enough to fit in a teaspoon with a radius of around 2cm. What would be the acceleration due to gravity on the surface of the crushed Earth? If you moved away from the crushed Earth a distance equal to the Earth's radius, what would be the acceleration due to gravity? 

SOLUTION Links to an external site.

  1. A 150 kg satellite is in orbit around the Earth 200km above the Earth's surface. What is the period of the satellite's orbit?

SOLUTION Links to an external site.

Newton's Law of Universal Gravity Practice Problems

Download Newton's Law of Universal Gravity Practice Problems Links to an external site. for more practice.

Download solutions Links to an external site. to the practice problems. 

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