1. Keep the Slinky in its box until further instructed.
Waves
Keep the Slinky in its box until further instructed.
Clear off your tables! (binders/folders/Slinky boxes) Paper/pencil only!

2. Slinky Lab Ground Rules:
You will have about seconds to do the assigned task.
Be GENTLE. Don’t shake too violently. The Slinky should NOT fall off of your table.
LIGHTS OFF = HANDS OFF.
Do not touch the Slinky again until instructed to. (Lights on)

3. What is a wave?
Wave = A disturbance/vibration that transmits energy through matter or space
A medium is a substance or material which carries the wave

4. Transverse
Vibrates perpendicular (90) to the direction of wave travel
Example: Electromagnetic waves
Animation courtesy of Dr. Dan Russell, Kettering University

5. Transverse Use your Slinky to demonstrate a transverse wave:
Work with a partner
One of you move your end of the Slinky back and forth (left and right, like a snake crawling), perpendicular to its stretched length.
The other student must hold his or her end of the Slinky still

6. Draw and label what your Slinky looked like when it created a transverse wave.

7. Longitudinal
Vibrates parallel (in the same direction) to the direction of wave travel
Example: sound waves
Animation courtesy of Dr. Dan Russell, Kettering University

8. Animation courtesy of Dr. Dan Russell, Kettering University

9. Longitudinal Are composed of:
Compressions, where the parts of the medium (coils of the Slinky) are CLOSER TOGETHER than normal
Rarefactions, where the parts of the medium are FARTHER APART than normal

10. Longitudinal Use your Slinky to demonstrate a longitudinal wave:
Work with a partner
Stretch it out along the table
One of you grasp and draw several coils of a stretched Slinky toward yourself
Release the coils
The other student must hold his or her end of the Slinky still

11. Draw and label what your Slinky looked like when it created a longitudinal wave.

12. Surface Waves A combination of longitudinal & transverse
Example: Ocean waves
Animation courtesy of Dr. Dan Russell, Kettering University

13. Electromagnetic Waves
Wave which can transmit its energy through a vacuum or empty space.
Example – light
Produced by the vibration of electrons within atoms on the Sun's surface
Travel through space until they reach Earth

14. Mechanical Waves
Not capable of transmitting its energy through a vacuum (space)
Require a medium in order to transport their energy from one location to another
Example – sound waves, seismic waves

15. Keep the Slinky in its box until further instructed.
Clear off your tables! (binders/folders/Slinky boxes) Paper/pencil only!

16. Slinky Lab Ground Rules:
You will have about seconds to do the assigned task.
Be GENTLE. Don’t shake too violently. The Slinky should NOT fall off of your table.
LIGHTS OFF = HANDS OFF.
Do not touch the Slinky again until instructed to. (Lights on)

17. There are four things we can measure for waves:
Wavelength
Frequency
Amplitude
Speed

19. Wavelength Distance What is length a measure of?
So what do you think a wavelength is?
The distance across 1 FULL wave
Distance
WAVELENGTH
WAVELENGTH

20. Which has a shorter wavelength?

21. Measuring Wavelength
Does this tell us the distance between the two waves?
Why not?
You have to measure the distance
between the same two points!
(crest to crest, trough to trough, etc.)

22. Wavelength – Transverse Waves
Waves with
_________________
wavelength have
more energy.
Stretch the slinky out across the table.
Make TRANSVERSE waves.
Try to create waves with a LONG wavelength.
Try to create waves with a SHORT wavelength.
a shorter
Which wave did you have to put more effort into creating?

23. Amplitude
The distance between the crest or trough and the wave’s resting position (wave height).
Crest
Amplitude
Resting
Position
Amplitude
Trough

24. Which has a larger amplitude?

25. What does amplitude tell us about a wave?
Which of these waves would cause more damage if it hit the shore?
Which has the larger amplitude?
Which wave has more energy?
THAT’S
AMPLITUDE!

26. Amplitude – Transverse Waves
Waves with
_________________
amplitude have
more energy.
Stretch the slinky out across the table.
Make TRANSVERSE waves.
Try to create waves with a LARGE amplitude.
Try to create waves with a SMALL amplitude.
a larger
Which wave did you have to put more energy into to create?

27. We’ve been looking at transverse waves…What about longitudinal?

28. We’ll start with wavelength…
There aren’t any crests or troughs in a longitudinal wave!
WAVELENGTH
WAVELENGTH

29. We look at the compressions and rarefactions instead.
Wavelength is the distance from:
Compression to compression
Rarefaction to rarefaction

30. Wavelength – Longitudinal Waves
Waves with
_________________
wavelength have
more energy.
Stretch the slinky out across the table.
Make LONGITUDINAL waves.
Try to create waves with a LONG wavelength.
Try to create waves with a SHORT wavelength.
a shorter
Which wave did you have to put more effort into creating?

31. On to amplitude…
Longitudinal waves don’t have a resting point… so what do we do?

32. Amplitude
We look at how compressed or how rarefied the spring or particles are.
More compressed = larger amplitude
Less compressed = smaller amplitude

33. Amplitude – Longitudinal Waves
Waves with
_________________
amplitude have
more energy.
Stretch the slinky out across the table.
Make LONGITUDINAL waves.
Try to create waves with a LARGE amplitude.
Try to create waves with a SMALL amplitude.
a larger
Which wave did you have to put more energy into to create?

34. Frequency
What does it mean that a friend comes over to your house “frequently”?
Can you take a guess as to what the “frequency” of a wave is?
The frequency of a wave tells us the number of waves that pass a given point in a certain amount of time.

35. What is the unit for frequency?
Frequency is measured in Hertz (Hz) – waves/sec.
If one full wave passes a point every second, it has a frequency of 1 Hz. (1 wave/1 sec = 1 wave/sec)
What is the frequency for 3 waves in 1 second?
What is the frequency for 6 waves in 3 seconds?

36. Which has a higher frequency?

37. How can you find the frequency of this wave?
Step 1: pick a point on the wave.
Step 2: count the waves that pass that point in ___ seconds.

38. Frequency – Transverse Waves
Stretch the slinky out across the table.
Have one person pick a point on the table and count how many waves pass that point
Have another person count to 10 seconds.
Make TRANSVERSE waves.
Try to create a HIGH FREQUENCY wave.
Try to create a LOW FREQUENCY wave.
Try to keep the amplitudes the same in both waves.

39. Frequency – Transverse Waves
Waves with
_________________
frequency have
more energy.
Stretch the slinky out across the table.
Have one person pick a point on the table and count how many waves pass that point
Have another person count to 10 seconds.
Make TRANSVERSE waves.
Try to create a HIGH FREQUENCY wave.
Try to create a LOW FREQUENCY wave.
Try to keep the amplitudes the same in both waves.
a higher
Which wave did you have to put more energy into to create?

40. Wave Speed
Option 1: Time how long a wave takes to get from point A to point B. A B

41. Wave speed = wavelength x frequency
Option 2:
Wave speed = wavelength x frequency
Wave Speed =
8 meters/second
Wavelength – 2 meters
Frequency –
4 Hz.
(4 waves pass every second)

42. Wave speed is affected by several factors
The type of wave
Example: Light vs sound (why you see lightning before you hear thunder)
The medium the wave is moving through
Example 1: You drop a penny into a pan of water & a pan of syrup – which hits first?
Example 2: yelling underwater as opposed to above water (in air).