Standing Waves Experiment https://phet.colorado.edu/en/simulations/wave-on-a-string

Use the Wave on a String Simulation for this lab.

1. For this first simulation, click Pulse on the top left, and the rulers and timer on the bottom right. Adjust the settings as given below to find the length and measured amplitude of the wave, as well as the time to dissipation. Record observations about the wave in the following questions. Be sure to stop the simulation between changes to the variables to get a uniform wave.

	Amplitude (cm)	Pulse Width (s)	Fixed/Loose End	Damping	Tension	Length of Wave (cm)	Measured Amplitude (cm)
Trial 1	0.75	0.5	Fixed	None	High
Trial 2	0.75	0.5	Loose	None	High
Trial 3	0.75	0.5	Fixed	None	Low

2. How did the wave change between Trial 1 and Trial 2 when the simulation switched from a fixed end to a loose end?

3. Describe how the wave changed when the tension went from high to low for the fixed end string.

4. For the following trials keep the simulation on Pulse. Pause the simulation immediately after a wave is shown to record the data below. Use slow motion to help you capture the wave on the screen. Then let the simulation continue until the wave dissipates.

	Amplitude (cm)	Pulse Width (s)	Fixed/Loose End	Damping	Tension	Length of Wave (cm)	Measured Amplitude (cm)
Trial 4	0.75	0.5	Fixed	Medium	High
Trial 5	0.75	0.5	Fixed	High	High
Trial 6	0.75	0.5	Fixed	Medium	Low
Trial 7	0.75	0.5	Fixed	High	Low

5. How does increased damping affect waves?

6. Can you double the measured amplitude of a wave? Make a simulation that causes two waves travelling along the same side of the string to collide. Record the variables used below to try this, as well as the measured amplitude before the collision and once the two waves converge. Use slow motion if needed to pause the simulations and measure the amplitude.

7. Can you make a point on the string with two waves travelling along it that does not move, or moves only a very little bit, from the reference line? Record the variables used below to try this and discuss what you discovered.

8. Switch to oscillate and experiment with the damping and tension to combine waves. Describe some of your observations here.