Earth & Space Science
In this activity, learners will investigate the relationship between mass and force to discover Newtons Law of Universal Gravitation using a Cavendish apparatus.
After completing this tutorial, you will be able to complete the following:
Newton's Law of Universal Gravitation builds upon his second law, which states that force is required to make an object accelerate. This all began with the story of Newton and the apple tree. Newton wondered what force was acting on an apple to make it accelerate toward the earth when it fell. He realized that the same force between the apple and the earth is the force of attraction that exists between any two objects in the universe.
Newton theorized in the 17th century that there is gravitational force acting between every object, and it is proportional to
The force between objects depends upon the mass of the two objects, and the distance between them. The relationship between the two masses is directly proportional to the force, so the greater the mass of one object, the stronger the force will be. The distance between the two objects also affects the force. The force is inversely proportional to the square of the distance between the two objects, so if the distance between two objects is cut in half, the force will be four times greater.
The universal gravitational constant was not able to be accurately measured however, until the 18th century when Henry Cavendish used a special devise to observe the relationship between the mass of objects and the distance between them.
The attraction between an object and the Earth can be felt when one tries to pick up a heavy object. In order to pick it up, one must overcome the attraction that the object has toward the Earth and the Earth has toward the object. This concept is what gives an object its weight.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Define the concept of force.Give examples of types of force.|
|Course||Earth & Space Science|
|Type of Tutorial||Concept Development|
|Key Vocabulary||acceleration, attraction, attractive force|