Sound is transmitted through vibrations. The length of a vibrating object affects the pitch of the sound it produces - shorter lengths vibrate faster and produce higher pitches. Sound moves as a wave through the particles of the transmitting medium, such as air, causing them to vibrate back and forth. Sound cannot travel through a vacuum because it is a mechanical wave that requires a material medium to propagate through.

1. SOUND Chapter 13 ( Phy)

2. Define
L
How does sound transfer from one point to another?? R

4. What is a vibration in sound????
Sound source

5. How does the length of a vibrating object affect sound?
Length of an object can change the vibration and cause the pitch to
change. Shorter materials vibrate faster than longer ones. The faster
a string, wire, or air in a tube vibrates, the higher the pitch of the
sound. For example, when you shorten the length of a guitar string it
makes a higher pitched sound.
So that the strings can be fretted and therefore made shorter, thus raising the
pitch

7. class activity, workbook page 72, Q1-3

8. Sound and the particle model of matter
Push
Particles are
close
together
Pull
Particles are
away from
each other

9. class activity, workbook page 72-73, Q4

10. Why do you think the movement of sound is described as a
sound wave??????( Workbook Q5) ( Homework)

11. Why do you think the movement of sound is
described as a sound wave??????( Workbook Q5)
We say sound is a wave because the air molecules move
back and forth while the sound travels along.

12. Class activity workbook page 74&75 ,Q6&Q7

13. Why cannot sound travel in a
vacuum???

14. The sound is a mechanical energy which can be produced only due to the
vibration produced in the material body. The mechanical waves need some
material medium for propagation. The vacuum has no material medium;
therefore, sound energy cannot propagate.
Why cannot sound travel in a
vacuum???

15. Class activity workbook page 75,Q8

16. Reflection of sound

17. Reflection of sound