Universal Gravitation Lab
Go to http://phet.colorado.edu/en/simulation/gravity-force-lab and click on Run Now.
Introduction:
Every object around you is attracted to you. In fact, every object in the galaxy is attracted to every other object in the galaxy. Newton postulated and Cavendish confirmed that all objects with mass are attracted to all other objects with mass by a force that is proportional to their masses and inversely proportional to the square of the distance between the objects' centers. This relationship became Newton's Law of Universal Gravitation. In this simulation, you will look at two massive objects and their gravitational force between them to observe G, the constant of universal gravity that Cavendish investigated.
Important Formulas:
Procedure: PhET Simulations Play with the Sims Physics Gravity Force Lab
1. Take some time and familiarize yourself with the simulation. Notice how forces change as mass changes and as distance changes.
2. Fill out the chart below for various objects at various distances.
3. Solve for the universal gravitation constant, G and compare it to published values.
Remember significant digits!
Mass Object 1 Mass Object 2 Distance Force Gravitation Constant,G
56.3 kg
22.2 kg
3.00m
9.1*10^-9 N
6.553*10^-11
20kg
60kg
3.00m
8.74*10^-9N
6.55*10^-11
60 kg
20 kg
6.00m
2.10*10^-9N
6.3*10^-11
42 kg
62 kg
3.00 m
15.54*10^-9N
5.37*10^-11
100 kg
50 kg
7.00 m
5.97*10^-9N
5.85*10^-11
50 kg
100 kg
8.00 m
4.69*10^-9N
6.06*10^-11
23kg
48kg
5.00 m
2.46*10^-9N
5.57*10^-11
10kg
28 kg
3.00m
3.03*10^-9N
6.49*10^-11
Average value of G: ________6.09*10^-11_____ Units of G: ___m^3/kgs___________
Published value of G: ____6.67*10^-11_______________ Source: __Universe today______________
How did your value of G compare to the published value you found? _____It somehow matched but there was some