Exam 2

Question 1

1 Angstrom

Answer 1

10^-10 m

Question 2

Speed of Light Facts

Answer 2

1/10 second to cross the
Atlantic. 8 minutes to get from the Sun
to the Earth. 4.3 years to reach Earth from
the nearest star

Question 3

Ole Romer

Answer 3

Used the eclipse of Jupiters moon to determine speed of light

Question 4

Fizeau-Foucault

Answer 4

Used a spinning mirror to determine speed of light.

Question 5

Michelson-Morley

Answer 5

Michelson and Morley performed an experiment with a rotating interferometer.

Question 6

Gamma Rays

Answer 6

given off naturally by radioactive materials, and are part of the fallout after a nuclear explosion. They have very short wavelengths, and can therefore travel through material, including lead, and can damage living tissue.

Question 7

X-Ray

Answer 7

given this name because their discover was unsure of what they were. They pass through flesh, but are absorbed by bone, which makes them useful for medical diagnostics. The wavelengths match the spacings between atoms in solids, which makes them useful for studies of material properties. Small
doses are safe, but large doses can be harmful to living tissue.

Question 8

UV

Answer 8

cause us to tan and help the skin to produce vitamin D. Large amounts are dangerous and may cause skin cancer. Most UV light from the sun is absorbed by the ozone layer. UV blacklights are used to make bright colors appear brighter.

Question 9

Visible Light

Answer 9

appears white as a whole, but is made of many colors. Red and violet light have wavelengths of 7500 and 4000 Å, respectively, which correspond to frequencies of 4x1014 and 7.5x1014 Hz.

Question 10

IR

Answer 10

transmit heat. They can be used to

see objects in the dark. They are also used for TV remote controls.

Question 11

Microwaves

Answer 11

very short radio waves, used in ovens. Also used for radar.

Question 12

Radio Waves

Answer 12

are at the low end of the frequency spectrum, are used

to broadcast radio and TV.

Question 13

nanometer

Answer 13

10^-9m

Question 14

red frequency

Answer 14

4x10^14 Hz

Question 15

violet frequency

Answer 15

7.5x10^14 Hz

Question 16

What light can pass through glass?

Answer 16

Visible light

Question 17

Speed of Light in Water

Answer 17

.75c

Question 18

Speed of Light in Glass

Answer 18

.67c

Question 19

Lunar Eclipse

Answer 19

Moon in Earths Shadow

Question 20

Solar Eclipse

Answer 20

Shadow of the Moon on the Earth

Question 21

Umbra

Answer 21

Total Eclipse

Question 22

Penumbra

Answer 22

Partial Eclipse

Question 23

Cones

Answer 23

Over 160,000 in each square millimeter of the fovea, None on the periphery, Responsible for sharp images, There are 3 types of cones, They contain photopigment molecules that absorb light and stimulate nerves, Provide color vision

Question 24

Rods

Answer 24

None on fovea, Responsible for peripheral vision, Sensitive to: dim light, motion, small variations in intensity

Question 25

Color blind

Answer 25

About 8% of males and 1% of females have some form

of color deficiency

Question 26

rayleigh scattering

Answer 26

Occurs when resonant frequencies are higher than the frequencies of the particles scattering, More effective at short wavelengths (the blue end of the visible spectrum).

Question 27

Reflection

Answer 27

occurs as light interacts with the free electrons in a material

Question 28

Concave mirror beyond focal

Answer 28

Real image, Inverted

Question 29

concave mirror within focal

Answer 29

• Virtual image, Upright

Question 30

convex mirror

Answer 30

Virtual image, Upright

Question 31

Refraction

Answer 31

Bending of a wave as it moves from one medium to another, A consequence of the fact that the wavespeed depends on the
medium.

Question 32

law of refraction

Answer 32

01 > 02 leads to n1 < n2

Question 33

mirages

Answer 33

Mirages occur because light travels faster in hot air than in cool air