Masses and Spring lab from http://phet.colorado.edu/ 

Learning Goal:  To explore the properties and relationships between masses and springs.

1.Put a 100 g weight on the first and the third springs. They should hang at the same level. Increase the stiffness of spring 3.
What happens when the stiffness of spring 3 is increased?
2.What happens to all the energy columns as the stiffness in increased? How do they differ from spring 1?
3.In the same configuration as step 2, decrease the stiffness of spring 3 What happens when the stiffness of spring 3 is decreased?
4.What happens to the energy columns as the stiffness is decreased? How do they differ from spring 1?
5.Where does the spring have maximum elastic potential energy?
6. Where is the gravitational potential energy the least?
7. Where is the kinetic energy zero?
8. Where is the elastic potential energy zero? 
9. Place the weights below on the end of spring #3 and fill in the data table below.  

Mass (g)
	Mass (kg)	Force - weight (N)
Hint:  mass (kg) x gravity = weight	Distance spring stretched (cm) 	
50	0.050	0.050 x 10 = 0.5 		
100				
250				

10. Using Hooke’s Law (Force = elasticity x distance) calculate the elasticity of spring #3.  

11. Set the stiffness of spring #3 to “hard”.Fill in the data table below.

Mass (g)
	Mass (kg)	Force - weight (N)
Hint:  mass (kg) x gravity = weight	Distance spring stretched (cm) 	
50	0.050	0.050 x 10 = 0.5 		
100				
250				

12.Using Hooke’s Law calculate the elasticity of spring #3 now.

13. Set the stiffness of spring #3 to “soft”.Fill in the data table below.
Mass (g)
	Mass (kg)	Force - weight (N)
Hint:  mass (kg) x gravity = weight	Distance spring stretched (cm) 	
50	0.050	0.050 x 10 = 0.5 		
100				
250				

14. .Using Hooke’s Law calculate the elasticity of spring #3 now. What did you find interesting about this third setup?

Using your data about k and displacement, Write down and test a procedure for determining the mass of the red, gold, and green masses. Show all data, a sample table might look like the one below.

	Mass (g)
	Mass (kg)	Force - weight (N)
Hint:  mass (kg) x gravity = weight	Distance spring stretched (cm) 	k	
Gold 						
red						
blue						

Compute the gravity for Jupiter, the moon, and planet X utilizing what you know or test about k, m, and x on these planets. Show all data. Compare the softness or hardness of the spring to the same spring on earth. Show your reasoning.