“Camera Obscura” by Abelardo Morell1

A laser beam comes vertically down and hits a flat mirror at 30° to the vertical.

Which way does the reflected beam go?

a) up/right, 30° from the horizontal

b) right, horizontal c) down/right, 30° below the

horizontal d) down/right, 60° below the

horizontal

30°

A laser beam comes vertically down and hits a flat mirror at 30° to the vertical.

Which way does the reflected beam go?

a) up/right, 30° from the horizontal

b) right, horizontal c) down/right, 30° below the

horizontal d) down/right, 60° below the

horizontal

30°

30°

30°

shiny reflective ball

??°A laser beam comes straight down and hits a shiny ball at the location shown.

At what angle from the vertical is the reflected beam?

a) 15° b) 30° c) 45° d) 60° e) 75° f) 90°

Slide 33-‹#›© 2015 Pearson Education, Inc.

An observer O, facing a mirror, observes a light source S. Where does O perceive the mirror image of S to be located?

1. 1 2. 2 3. 3 4. 4 5. Some other location 6. The image of S cannot be seen by O when O and S are

located as shown.

You stand in front of a mirror. How tall does the mirror have to be so that you can see yourself entirely?

a) same as your height b) less than your full height but

more than half your height c) half your height d) less than half your height e) any size mirror will do

How big a mirror do we need?7

Mir

ror

Image

0.10 mG

D

B

CA

E

HF

1.50 m

©2005 by Prentice Hall, Inc.A Pearson Company

Figure Number: 23 07

GiancoliPhysics: Principles with Applications, 6e

AACKWDW0

How big a mirror do we need?8

Mir

ror

Image

0.10 mG

D

B

CA

E

HF

1.50 m

©2005 by Prentice Hall, Inc.A Pearson Company

Figure Number: 23 07

GiancoliPhysics: Principles with Applications, 6e

AACKWDW0

Does the size of the mirror depend on the distance you stand from the mirror?

a) Yes b) No c) Depends on the person d) Depends on the mirror

ab

c

d

A light ray comes out of a slow medium into a fast one. Which of these rays is a

possible path?

a

b

c dA light ray comes out of a slow medium into a fast one. Which of these rays is a

possible path?

ConcepTest 23.4a Refraction I

1

air air

Parallel light rays cross interfaces from air into two different media, 1 and 2, as shown in the figures below. In which of the media is the light traveling faster?

1) medium 1 2) medium 2 3) both the same

2

A fish swims below the surface of the water at P. An observer at O sees the fish at

1. a greater depth than it really is.2. the same depth.3. a smaller depth than it really is.

Explanation

A fish swims below the surface of the water. Suppose an observer is looking at the fish from point O' straight above the fish. The observer sees the fish at

1. a greater depth than it really is.2. the same depth.3. a smaller depth than it really is.

Explanation

ConcepTest 23.5a Gone Fishin’ I To shoot a fish with a gun, should

you aim directly at the image, slightly above, or slightly below?

1) aim directly at the image 2) aim slightly above 3) aim slightly below

ConcepTest 23.5b Gone Fishin’ II

1) aim directly at the image 2) aim slightly above 3) aim slightly below

To shoot a fish with a laser gun, should you aim directly at the image, slightly above, or slightly below?

More stuff explained20

Refractive Index of Air

Temperature (ºC)

100FFreezing

“Heat Shimmer”21

“Mirage”22

n big

n small