Module 4—Gravitational Force

Lesson Summary

 

In this lesson you explored the following questions:

By measuring the force of attraction between two masses using a torsion balance, Cavendish determined the value for the gravitational constant (G) and, indirectly, also weighed Earth.

 

 

 

Cavendish’s work verified Newton’s law of universal gravitation and, in doing so, enabled us to understand gravitational fields beyond Earth’s surface. This allows us to calculate the weight of objects on the surface of other planets and to understand how the force of gravity changes as you approach or move away from a very large mass, such as a planet.

 

Lesson Glossary

 

density: the mass per unit volume of an object

 

proportionality constant: the constant value of the ratio of two variables

 

torsion balance: a measuring instrument designed to measure small forces by the torsion (twisting) they cause in a thin wire