Lights,Sound.....Action!

1. Lights, Sounds…. Action!
Prepared by: JM Ramos

2. Speed of Sound
• Sound
–Longitudinal wave that needs a medium
in order to propagate
–The velocity which sound waves
propagate through a medium depends
upon the density and elasticity of the
medium

3. Speed of Sound
• Elasticity
–Ability of the material to undergo
temporary change in its size, shape
or volume when a force is applied
on it

4. Speed of Sound
• Elastic modulus
–The ratio of the force applied per
unit area of the material to a
fractional change in its size, shape
or volume.
–High and Low Elastic Modulus

5. Speed of Sound
• Speed of sound in Solid
• Speed of Sound in Liquid
• Speed of Sound in Gas

6. Speed of Sound
• Speed of sound in Solid
• Speed of Sound in Liquid
• Speed of Sound in Gas

7. Speed of Sound
• Effect of Temperature
• Increasing the temperature
decreases density in as much as
the materials expands

8. Mach Number
• The ratio of the speed of the
source of the sound to the speed
of the sound in the medium
• Shockwaves/sounds wave length

9. Mach Number
• Subsonic
–If the speed of the source of sound
is less than the speed of sound in
the medium

10. Mach Number
• Supersonic
–If the speed of the source of the
sound is greater than the speed of
the sound in the medium

11. Mach Number
• When the speed of the source
exceeds the speed of sound, it is said
to ‘break the sound barrier.”
• The source forms a high pressure
shock wave
• This is what an observer hears as
sonic boom when fighter jets pass
over

12. Mach Number
• Shockwaves have an important
application in medicine
• They are used to break the kidney
stones or gallstones in a non-invasive
procedure called extracorporeal
shockwave lithotripsy

13. Light interaction with Matter
• Shockwaves have an important
application in medicine
• They are used to break the kidney
stones or gallstones in a non-invasive
procedure called extracorporeal
shockwave lithotripsy

14. Light interaction with Matter
• Shockwaves have an important
application in medicine
• They are used to break the kidney
stones or gallstones in a non-invasive
procedure called extracorporeal
shockwave lithotripsy

15. Light interaction with Matter
• Absorption
– Take place when lights transfer some or all of
its energy to the medium

16. Light interaction with Matter
• Refraction
– Bending of light
• Index of refraction
– Greater index of refraction means greater
bending of light

17. Light interaction with Matter
• Transparent body
– Allows light pass through it
• Translucent body
– Scatters the light passing through it so that
object behind it are not clearly seen
• Opaque body
– Does not transmit light at all

18. Color of Light and Energy

19. Dispersion of Light by a Prism
• Prism
• rainbow

20. The End !!