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Physics 42L – Spring 2008 Class Notes Alex Beutel 1 1.1 April 9, 2008 Mirrors l s l β≈ r l γ≈ s α+θ =β α≈ −θ + β = γ α + γ = 2β l l 2l += ss r r f= 2 1 1 1 += ss f Looking at Figure 32-10 (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) Ray diagram: • Parallel Ray => “through” the focal point • Central ray => incidence is equal to reflection • Focal Ray => parallel to center line • Radial Ray => reflects straight back y s =− =m y s (11) 2 April 11, 2008 n1 n2 1 + = (n2 − n1 ) s s r 1 (12) Lens makers formula (n − 1) 1 1 − r1 r2 = 1 f (13) 3 April 14, 2008 The eye is able to relatively compare distances by the angle through the lens on the retina. Eye can only contract and decrease focal length. 1. Normal eye - relaxed focal point lives on retina 2. Short sighted - relaxed focal point is in front of the retina, fix with a diverging lens 3. Far sighted - relaxed focal point is behind the retina, can squeeze muscle to compensate (but headaches) Near point for the distance of most distinct vision - 10 inches for young eye. Most distinct image is at near point. Simple Magnifier y xnp y θ ≈ tan θ = f θ xnp M= ≈ θ0 f θ0 ≈ tan θ0 = (14) (15) (16) 4 April 16, 2008 Telescope y = fo tan α ≈ fo α y = fe tan θ ≈ fe θ fo θ M = =− α fe (17) (18) (19) (20) Microscope mc = xnp fe (21) 5 April 18, 2008 s= 1 E×B µo (22) Polarization - vector direction of an Electric Field in EM wave Axis of Polarization - direction of E 2 5.1 Malu’s Law | E | =| Eo | cos θ I1 = Io cos θ 2 (23) (24) 3 

Document Info

Posted By:

Alex Beutel

Date:

Sunday, April 20, 2008

School:

Duke University

Class:

Physics 42L

Tags:

• notes
• Optics
• Physics
• Dr. Brown

About this Document

These are very basic notes from Dr. Brown's lectures on optics.