{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

p2f10_lec10_intensity_refraction_and_interference

# p2f10_lec10_intensity_refraction_and_interference - Physics...

This preview shows pages 1–6. Sign up to view the full content.

1 Physics 1200 Class 10 Wave intensity Poynting vector Sound level Test Q&A (after) Interference Refraction Two-slit Interference

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2 Intensity: a definition Intensity is defined as the average rate of energy transfer (power, P ) per area, through a surface. The units of intensity are watts/meter² (W/m 2 ). A P I =
3 Intensity and EM waves tells us the intensity and direction of an EM wave. varies with time. We work with the time- averaged Poynting vector, ( Intensity) . 0 1 Poynting vector S E B μ = × = r r r 0 0 1 1 2 m m I S EB E B μ μ = = = S r S r Because E m = cB m , the expression for intensity can be written: 2 2 0 0 2 2 m m E cB I c μ μ = =

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
4 Sound wave intensity 2 2 1 2 where is displacement amp. m m I v s s ρ ϖ = 2 2 where is pressure amp. m m p I p v ρ = Sound level, β , is defined as: 0 10log I I β = ÷ where I 0 = 10 -12 W/m² (the lower limit of human hearing)
5 Interference Waves of the same frequency from two sources will add together at each point in space (superposition principle). If the phases of the two waves are different, interference effects occur. (remember phasors?) φ φ = ÷ 0 2 0 For two equal waves of intensity I and phase difference 4 cos 2 total I I

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 20

p2f10_lec10_intensity_refraction_and_interference - Physics...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online