What is the difference between diffuse and specular reflection?
Plane Mirror +-
State the Law of Reflection in words. State the Law of Reflection in mathematical terms.
Sample Problem: A ray of light reflects from a plane mirror with an angle of incidence of 37 o. If the mirror is rotated by an angle of 5 o, through what angle is the reflected ray rotated? i = 37 0
Sample Problem: Standing 2.0 m in front of a small vertical mirror, you see the reflection of your belt buckle, which is 0.70 m below your eyes. What is the vertical location of the mirror relative to the level of your eyes? If you move backward until you are 6.0 m from the mirror, will you still see the buckle, or will you see a point on your body that is above or below the buckle? Explain
+- object located 5 cm in front of mirror
There are two types of spherical mirrors shiny
Show how Law of Reflection still applies.
What is the relationship between R and f?
+ - Rays parallel to the principal axis all pass through the focus for a spherical concave mirror.
The three “principal rays” to construct an image for a spherical concave mirror are:
CF
CF
CF
CF
CF
CF
Problem: Construct 2 ray diagrams to illustrate what happens to the size of the image as an object is brought nearer to a spherical concave mirror when the object outside the focus. Name the images produced.
Problem: Repeat the previous problem for an object which is brought nearer to the mirror but is inside the focus. Name the images produced.
Sample Problem: A spherical concave mirror, focal length 10 cm, has a 2-cm high object placed 5 cm from it. Draw a ray diagram and construct the image. F C
Concave Convex
Focal length (f) Magnification (M) Image Distance
Solution: A spherical concave mirror, focal length 20 cm, has a 5-cm high object placed 30 cm from it. a)Calculate the position, magnification, and size of the image. b)Name the image
Problem: A spherical convex mirror, focal length 15 cm, has a 4-cm high object placed 10 cm from it. a) Use the mirror equations to calculate i.the position of image ii.the magnification iii.the size of image b) Name the image
n1n1 n2n2 11
n1n1 n2n2 11
Problem: Light enters an oil from the air at an angle of 50 o with the normal, and the refracted beam makes an angle of 33 o with the normal. a)Draw this situation. b)Calculate the index of refraction of the oil. c)Calculate the speed of light in the oil
Problem: Light enters water from a layer of oil at an angle of 50 o with the normal. The oil has a refractive index of 1.65, and the water has a refractive index of a)Draw this situation. b)Calculate the angle of refraction. c)Calculate the speed of light in the oil, and in the water
Problem: Light enters a prism as shown, and passes through the prism. a)Complete the path of the light through the prism, and show the angle it will make when it leaves the prism. b)If the refractive index of the glass is 1.55, calculate the angle of refraction when it leaves the prism. c)How would the answer to b) change if the prism were immersed in water? 30 o 60 o glass air
Problem: Light enters a prism made of air from glass. a)Complete the path of the light through the prism, and show the angle it will make when it leaves the prism. b)If the refractive index of the glass is 1.55, calculate the angle of refraction when it leaves the prism. 30 o 60 o glass air
n1n1 n2n2
Binoculars use a combination of prisms that reflect the incoming light. As long as the incident angles exceed the critical angle, the light will be reflected.
Light enters the fiber optic tube at an angle above the critical angle and is thus totally reflected down the ‘light pipe’ to the other end. For commercial use, two different glasses are used, wrapped in a protective cover. Which must have the greater index of refraction, the core or the cladding?
Problem: What is the critical angle of incidence for a gemstone with refractive index 2.45 if it is in air? If you immerse the gemstone in water (refractive index 1.33), what does this do to the critical angle of incidence?
Solution: The glass core of an optical fiber has an index of refraction of The index of refraction of the cladding is What is the maximum angle a light ray can make with the wall of the core if it is to remain inside the fiber?
There are two types of lenses.
A lens can be modeled as a combination of prisms
We use the same principal rays we used for mirrors. ◦ the p-ray, which travels parallel to the principal axis, then refracts through focus. ◦ the f-ray, which travels through focus, then refracts parallel to the principal axis. ◦ the c-ray, (or m-ray) which travels through the MIDDLE of the lens and continues without bending. You must draw 2 of the 3 principal rays when constructing an image.
CFF2F + -
CFF + -
CFF + -
CFF + -
CFF + -
Problem: A converging lens, focal length 20 cm, has a 5-cm high object placed 30 cm from it. a)Draw a ray diagram and construct the image. b)Use the lens equations to calculate i.the position of image ii.the magnification iii.the size of image c)Name the image
Problem: A converging lens, focal length 10 cm, has a 2-cm high object placed 5 cm from it. a)Draw a ray diagram and construct the image. b)Use the lens equations to calculate i.the position of image ii.the magnification iii.the size of image c)Name the image
+ -
Problem A diverging lens, focal length -15 cm, has a 4-cm high object placed 10 cm from it. a) Draw a ray diagram and construct the image. b) Use the lens equations to calculate i.the position of image ii.the magnification iii.the size of image c) Name the image