1. Mechanical Waves and Energy Transfer
U2C1A3 RS
Mechanical Waves and Energy Transfer

2. Read the purpose on page 119.
Start RS U2C1A3
Read the purpose on page 119.
How waves transfer energy from a source to a receiver?

3. We Think….
How does energy get transferred from you or your friend, since none of the coils you are holding onto travel all the way to your friend’s end?

4. What does the person at the other feel when the pulse reaches that end?
Do you think energy is being transferred from the hand #1 generating the pulse to the hand at the other end (hand #2)? Why do you think so?

5. Does a transverse pulse with larger amplitude seem transfer more, less, or the same amount of energy as a pulse with smaller amplitude? How do you know?
A E
A E

6. wave movie

7. No!
4 and 5
A. each individual coil transfers energy to the next coil causing it to move side to side
B. the coil’s position before & after the pulse passes is the same

11. decreases
frequency,  wavelength
(opposite ends of the alphabet)

14. more energy b/c the person feels a stronger push on their hand
Amplitude, Energy
(same end of the alphabet)

15. compression (longitudinal) wave
Motion 
Force 

16. start compression waves
wave movie

17. more energy b/c you feel a stronger push on your hand
Yes b/c the person holding the other end of the slinky feels a push. Energy is transferred from coil to coil until it reaches the hand on the other end
more energy b/c you feel a stronger push on your hand

18. 12. What does each individual coil do as the compression pulse passes by?
each coil moves forward then backwards to its original position; each coil transfers energy to the next coil

19. wave movie

22. more energy b/c the person feels a stronger push
frequency,  wavelength
(opposite ends of the alphabet)
more energy b/c the person feels a stronger push

23. wave movie

24. Amplitude, Energy more energy b/c the person feels a stronger push
(same end of the alphabet)

25. Make Sense of Your Ideas

26. 1. What is the difference between transverse and compression waves?

27. compression wave transverse wave Direction of FORCE Direction of WAVE

28. transverse wave: direction of force  direction of wave
compression wave: direction of force and direction of wave are the same direction 

29. Here is what the answer key says….

31. Each coil transfers energy to the next coil
Each coil transfers energy to the next coil. After the wave passes the coil returns to its original position.

32. 3.

33.  Frequency,  Wavelength

34. There is a change in motion The receiver feels a push on their hand

35.  Frequency, Energy
 Amplitude, Energy

36.  Frequency,  Energy
 Amplitude,  Energy

37. 5.

38. Summarize your Make Sense of Your Ideas answers.

39. Consensus Ideas
Types of waves:
transverse wave: direction of force  direction of wave
compression wave: direction of force and direction of wave are the same direction 

40. Consensus Ideas
Properties of waves:
 Frequency, Energy
 Amplitude, Energy
 Frequency,  Wavelength