1. Go tohttps://phet.colorado.edu/sims/html/masses-and-springs/latest/masses-and-springs_en.html
2. Select Lab
3. Set the Spring Constant (in the Spring Constant 1 Box) to some middle value
4. Select "display natural length" and "Mass Equilibrium"
5. Ensure that gravity is 9.8 m/s²
6. Set damping to lots.
7. Ensure that simulation is on play (Pause botton showing)
8. Select the known mass and hang it on the spring.
9. Drag the ruler from the toolbox to measure the extension of the spring.
10. Set up a table with headings as in the diagram below

Mass m (g)	Extension (cm)	Extension (m)	Weight (N)

1. Vary the mass at least 8 times and measure and record the corresponding extension.
2. Complete the table for all your data.
3. Plot a graph of Weight vs Extension (m)
4. Include the trendline
5. Display the equation of the line on your graph

From the slope of your graph ,determine the spring constant.

Method 2

1. Do not change the spring constant from method 1 above.
2. Remove the ruler and drag the stopclock from the toolbox.
3. Remove the displacement.
4. Set the damping to none
5. Pause the simulation
6. Select a mass
7. Play the simulation
8. Set up a table with headings as below

Mass (g)	Time for 20 oscillations	Average Period T (s)	T2 (s2)
t1 (s)	t2 (s)	average t (s)

1. Carefully start the stop clock and measure the time for 20complete oscillations.
2. Repeat steps 6 and 7
3. For 8 different masses complete the table of values
4. Plot a graph of T² vs m in kg
5. Include the trendline
6. Display the equation of the trendline on the graph
7. Use the slope of your graph and equation (3) to determine the spring Constant