Lab - Properties of Waves in Springs

Closeup image of a spring.

Learning Intentions

  1. To learn some of the vocabulary involving waves.
  2. To learn how physical waves travel through springs.

Safety

Springs can be dangerous. Do not let go of the spring when it is extended, as it can seriously injure your partner.

Safety with Elastic Materials


Notes

Lower frequency things happen less often

Higher frequency things happen more often

Kung Fu Panda – Slow Motion (1:15)


Part 1 - Pre-Lab Questions

Use the Internet to find answers to the following questions.

  1. What is the amplitude of a wave?
  2. What is the frequency of a wave?
  3. What is the period of a wave?
  4. What unit is used to measure frequency?
  5. What is a medium?
  6. What is the difference between an impulse wave and a periodic wave?
  7. What is a standing wave?
  8. In a standing wave, what are nodes and anti-nodes?
  9. Draw a series of surfing waves. Label the amplitude.
    1. What is the medium of the wave?
    2. What type of wave is it?
    3. What is the period of the wave?
  10. Draw a single tsunami wave and label the amplitude.
    1. What is the medium of the wave?
    2. What type of wave is it?
    3. What is the period of the wave?

After answering all the questions, show your answers to the teacher to get your spring for the next part.

Part 2 - Spring Lab

  1. Stretch the spring out on the floor between two partners. Align the spring with the line of the floor tiles, so that you can determine the amplitude of the waves.
  2. Have the third partner set up to record each wave in slow motion, in landscape mode. Make sure that they are recording the entire length of the spring, viewed horizontally.
    In the video, a positive amplitude should be up, and a negative amplitude should be down.
  3. Have each partner practice sending impulse waves, with both positive and negative amplitudes.
  4. Record slow-motion videos of the following waves:
    1. A positive impulse wave.
    2. A negative impulse wave.
    3. A positive impulse wave meeting a positive impulse wave.
    4. A negative impulse wave meeting a negative impulse wave.
    5. A negative impulse wave meeting a positive impulse wave.
    6. Touching a node of a standing wave with a pencil.
    7. Touching an anti-node of a standing wave with a pencil.
    8. A standing wave with as many nodes as possible.

Part 3 - Data and Analysis

  1. What happens when a positive impulse wave reaches your partner's hand at the end of the spring?
  2. What happens when a negative impulse wave reaches your partner's hand at the end of the spring?
  3. What happens when a positive impulse wave meets a positive impulse wave?
  4. What happens when a negative impulse wave meets a negative impulse wave?
  5. What happens when a negative impulse wave meets a positive impulse wave?
  6. If you had to touch a node or an anti-node, which would you choose? Why?
  7. How many nodes were you able to create in a standing wave? How could you create more nodes? Is there a limit to how many nodes you could create?