# Physics 123 23. Light: Geometric Optics 23.1 The Ray Model of Light 23.2 Reflection - Plane Mirror 23.3 Spherical Mirrors 23.5 Refraction - Snell’s law

• View
216

2

Tags:

Embed Size (px)

### Text of Physics 123 23. Light: Geometric Optics 23.1 The Ray Model of Light 23.2 Reflection - Plane Mirror...

• Slide 1
• Slide 2
• Physics 123
• Slide 3
• 23. Light: Geometric Optics 23.1 The Ray Model of Light 23.2 Reflection - Plane Mirror 23.3 Spherical Mirrors 23.5 Refraction - Snells law 23.7 Converging and Diverging Lenses
• Slide 4
• Reflection ii rr i = r Angle of incidence equals the angle of reflection
• Slide 5
• Image in a Plane Mirror
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• d o = d i
• Slide 11
• Spherical Mirrors Concave mirror Convex mirror
• Slide 12
• Concave Mirror radius = r focus = f r f f = r / 2
• Slide 13
• Concave Mirror A parallel ray reflects through the focus
• Slide 14
• Concave Mirror Solar Cooker!
• Slide 15
• Concave Mirror A ray through the focus reflects parallel
• Slide 16
• Concave Mirror Image is inverted, real, reduced
• Slide 17
• Concave Mirror Equation 1 / d o + 1 / d i = 1 / f
• Slide 18
• Concave Mirror Problem A 3 cm high candle is located 5 cm from a concave mirror whose radius of curvature is 20 cm. What are the characteristics of the image?
• Slide 19
• Concave Mirror Problem f = 10 cm 1/d o + 1/ d i = 1/f 1/5 + 1/ d i = 1/10 1/ d i = - 1/10 d i = - 10 cm The image is 10 cm behind the mirror, virtual, upright, and magnified 2X m = - d i / d o
• Slide 20
• Concave Mirror Problem Makeup mirror! If the object is within the focus of the concave mirror the image is enlarged (magnified), upright but virtual its all in your head!!!
• Slide 21
• Convex Mirror
• Slide 22
• Image will ALWAYS be reduced, virtual, upright
• Slide 23
• Jurassic Park! Rear View Mirror Objects in the mirror are closer than they appear!
• Slide 24
• Convex Mirror Equation 1 / d o + 1 / d i = 1 / f Note: f is negative d i is negative
• Slide 25
• Convex Mirror Problem A 3 cm high candle is located 5 cm from a convex mirror whose radius of curvature is 20 cm. What are the characteristics of the image?
• Slide 26
• Convex Mirror Problem f = - 10 cm 1/d o + 1/ d i = 1/f 1/5 + 1/ d i = - 1/10 1/ d i = - 3/10 d i = - 3.3 cm The image is 3.3 cm behind the mirror, virtual, upright, and reduced in size m = - d i / d o m = 1 / 3
• Slide 27
• Refraction ii rr
• Slide 28
• Index of Refraction n = sin i / sin r
• Slide 29
• Refraction Problem The index of refraction of glass is 1.5. A ray of light is incident on a glass pane at an angle of 60 0. Calculate the angle of refraction.
• Slide 30
• Refraction Problem n = sin i / sin r 1.5 = sin 60 0 / sin r 1.5 = 0.866 / sin r sin r = 0.866 / 1.5 sin r = 0.58 r = 35 0
• Slide 31
• Converging (convex) Lens
• Slide 32
• Converging Lens When the object is outside the focus, the image is real and inverted
• Slide 33
• Converging Lens When the object is inside the focus, the image is virtual, upright, and enlarged.
• Slide 34
• Diverging (concave) Lens
• Slide 35
• Slide 36
• The image is ALWAYS reduced, upright, virtual
• Slide 37
• Lens Problem A 35 mm slide projector uses a converging lens with f = 20 cm. The screen is 3 m away. How far is the slide from the lens?
• Slide 38
• Lens Problem 1/d o + 1/ d i = 1/f 1/d o + 1/ 300 = 1/20 1/d o = 1/20 - 1/ 300 d o = 21. 4 cm m = - d i / d o m = - 300 / 21.4 m = -14 Image is real, inverted, magnified
• Slide 39
• Thats all folks!

Recommended ##### ) PrinciplesInstructor:John L. Minor orange, yellow, green, ... When light (EM energy) strikes the boundary of some type of matter, ... according to Snell’s Law. 1
Documents Documents