CP Lab
SPRING TRAINING(A Super Slinky)
PURPOSE:
To study the motion of waves and find out properties about waves.

DISCUSSION:
All waves exhibit similar qualities. In this lab you will observe a wave's behavior as it travels, reflects, interferes, and changes media. Remember that ALL waves we will discuss in the future behave in a similar way as what you will observe these mechanical waves doing.


PROCEDURE AND QUESTIONS:

Wave Motion and Refraction
Step 1: While your partner holds one end very securely on a smooth surface, pull the other end until the slinky is stretched somewhat tight.

  • A transverse wave is a wave in which the particles move perpendicular to the direction the wave is moving.
  • A longitudinal wave has the particles moving in the same direction as the wave is moving.
  • To generate transverse waves, quickly jerk the slinky sideways(not up and down) on the floor. It work best to send individual jerks, NOT a periodic pulse.
  • To generate longitudinal waves, squeeze about 10 coils of wire together and release.
  • Hang on tight. Don't let the slinky get the best of you.
    •        Step 2: Send some transverse pulses across the floor. Because of friction with the floor, the amplitude or displacement (height) of the pulse will decrease.

    Question 1: Does the pulse shape change (not the amplitude, the general shape)?

    Question 2: Does the speed change?

    Step 3: Shake some pulses of different sizes and shapes.

    Question 3: Does the speed depend on the pulse size and shape?

    Step 4: The Mediumis the material a wave passes through like air, water, metal, etc. Change the tension in the spring by lengthening or shortening the spring. Shake more pulses.

    Question 4: Does tension affect the speed of the wave? How?

    Question 5: Would changing the tension act as the same or a different medium?

    Wave Interference
    Step 5: To view what happens in this part, it works best to have the observer placedbehind one of the senders by about 5 to 10 yards. Send some transverse pulses of various sizes towards each other on one side of the slinky.

    Question 6: Do the pulses pass through each other or do they rebound? Explain what you saw?

    Question 7: What happens to the displacements (amplitude) of the pulses as they meet on same and opposite sides?

    Step 6: Send some transverse pulses of the same size on opposite sides of the spring.

    Question 8: What happens when they meet?

    Wave Speed

    Step 7: Create a standing wave. Use a ruler to determine the wavelength of the wave. Use a stopwatch to determine the period of the wave. (What will you measure for the period?) Record your data in a table.

    Step 8: Repeat for 2 different waves for a total of 3 waves. (Do not change anything other than how "fast" you move your hand up and down)

    Question11: Calculate the speed of each wave.

    Question 12: As you decrease the wavelength, what happend to the wave frequency (how often you moved your hand up and down)?

    Question 13: How do the speeds of all you waves comapare?