Name(s): ______

PHYSICS

Slinky Lab

Pre-Lab Questions on Longitudinal Waves:

  1. Longitudinal waves occur when the “vibration” (in this case the movement of your hand) is parallel to the direction of the wave motion. Make a diagram of what the coils will look like as the wave travels along the slinky.
  1. If a piece of yarn is tied to the slinky, predict what will happen to the yarn as the wave travels along the slinky? Explain why you think this outcome will take place.
  1. Predict what will happen to the coils of the slinky as the wave reaches the endpoint? Explain why you think this outcome will take place.

Pre-Lab Transverse Questions:

  1. Transverse waves occur with the direction of “vibration” is perpendicular to the direction of wave motion. Make a diagram of what the slinky will look like as the wave travels along the slinky.
  1. Predict what will happen to the yarn as the wave travels along the slinky? Explain why you think this outcome will take place.
  1. Predict what will happen to the slinky as the wave reaches the endpoint?

Pre-lab Questions on Wavelength, Frequency, and Amplitude prediction

  1. Define wavelength, frequency and amplitude in the space below.
  1. What will happen if you shake the spring faster for a transverse wave? Explain why you think this outcome will take place.
  1. What will happen if you increase the distance over the transverse wave is displaced? (move your hand a farther distance back and forth) Explain why you think this outcome will take place.
  1. What would you need to do to increase the number of waves traveling through the slinky and one time?

Pre-Lab Questions on Interference

  1. A pulse occurs when a single cycle or vibration is sent through the slinky. Interference occurs when two waves generated from a pulse meet. If you send a single pulse down the slinky, what will happen to the pulse when it reaches the endpoint? Explain why you think this outcome will take place.
  1. Sketch what will happen if two pulses (perpendicular to motion) crash into each other from opposite ends of the spring on the same side of the spring? (meaning both pulses are sent from the left to the right).
  1. Sketch what will happen if two crash into each other from opposite ends of the spring and opposite sides of the spring?

Procedure on Longitudinal Waves:

  1. Be quiet when you are in the hallway, other kids are trying to learn.
  2. Tie pieces of string or yarn at the beginning, middle, and end to the loops of the slinky.
  3. With a partner to help pull the slinky out on a smooth floor to a length of about 6 to 10 meters.
  4. One student will firmly hold the slinky at one end of the slinky.
  5. The second student will grasp the stretched slinky about a meter from one end. Pull the meter of slinky together toward yourself and then release the compressed coils.

Make the following observations:

  1. What happens to the pieces of yarn as the wave moves through the slinky?
  1. What happened to the slinky as the wave traveled to the endpoint?
  1. Does your pre-lab predictions match you’re observations?

Transverse Waves Procedure:

  1. With a partner to help pull the slinky out on a smooth floor to a length of about 6 to 10 meters.
  2. One student will firmly hold the slinky at one end of the slinky
  3. Practice moving your hand very quickly back and forth at right angles to the stretched spring until you can produce a pulse that travels down the slinky.

Make the following observations:

  1. What happens to the pieces of yarn as the wave moves through the slinky?
  1. What happened to the slinky as the wave traveled to the endpoint?
  1. Does your prediction match the diagram above?

Wavelength, Frequency and Amplitude Procedure:

  1. With a partner to help pull the slinky out on a smooth floor to a length of about 6 to 10 meters.
  2. One student will firmly hold the slinky at one end of the slinky
  3. Practice moving your hand very quickly back and forth at right angles to the stretched spring until you can produce multiple waves that travel down the slinky.
  4. Practice moving your hand back and forth various distances.

Make the following observations:

  1. How did you move your hand in order to create higher frequency waves?
  1. How did you move your hand to create greater amplitude?
  1. How did you move your and to create longer wavelength?
  1. Based on your observation, what do you think the relationship between frequency and wavelength is? Explain.

Interference Procedure:

  1. Generate single pulses simultaneously from opposite ends of the stretched Slinky.
  2. Send two pulses of approximately equal amplitudes toward each other on the same side of the spring.
  3. Repeat the experiment, but with the two pulses traveling on opposite sides of the spring.

Observations:

Do the observations during the procedure match your predictions? If they do not, redraw diagrams to reflect your observations.