# QUIZ 1 - Pinhole Flashcards Preview

## AP Physics 2 > QUIZ 1 - Pinhole > Flashcards

Flashcards in QUIZ 1 - Pinhole Deck (24)
1
Q

What happens to the shadow if the distance from the source to the object is decreased?

A

2
Q

What is the shadow from a point source called?

What is the shadow from an extended source called?

A

Shadow from a point source is called: umbra

Shadow from an extended source is called: penumbra

3
Q

What is the evidence that light travels in straight lines?

A
• a source of light (sun) casts distinct shadows
• the beam from laser point is straight
4
Q

What is the evidence that light moves?

A

it bounces off mirrors (starts at one point and ends in another)

5
Q

How many rays are coming out of a light source?

A

very large but NOT ∞ # of rays

6
Q

Why is it impossible for us to see the beam of light unless there is fog/dust?

A

Fog/dust scatters the rays of light into our eyes

7
Q

What is the UMBRA?

A

Darkest shadow (formed by a point source)

8
Q

What is the PENUMBRA?

A

Partial shadow (formed by extended source)

9
Q

When light strikes an object what can happen?

A
1. Reflected
2. Scattered (translucent material)
3. Absorbed (thermal energy)
4. Transmitted (transparent material)
10
Q

What was the old theory of the speed of light?

A

People used to believe that light had an ∞ velocity

11
Q

What is the current theory of the speed of light?

A

The speed of light is constant: 2.99 x 10^8 m/s

Represents the cosmic “speed limit” for matter & energy in the universe

12
Q

Who proved that the speed of light was constant?

A

Alfred Michelson

Galileo helped out (earlier)

13
Q

What happens as the distance from the pinhole - screen is changed?

A

PINHOLE - SCREEN:

• Small distance: small image, high intensity
• Large distance: large image, low intensity (same # rays hitting a larger area)
14
Q

What happens as the distance from the source - pinhole is changed?

A

SOURCE - PINHOLE:

• Small distance: large image
• Large distance: small image
15
Q

What happens when the size of the pinhole is changed?

A

SIZE PINHOLE:

• Small pinhole: small image, sharp (no overlap), low intensity (fewer rays can go through)
• -* Large pinhole: large image, fuzzy (overlap), high intensity (more rays)
16
Q

What happens if there are 2 pinholes instead of 1?

A

2 PINHOLES:

• 2 holes = 2 reproductions
• They can be completely separate or they can overlap
17
Q

What does transparent mean?

A

almost ALL light passes through → no scattering

18
Q

What does translucent mean?

A

SOME light passes through

light is scattered as it passes through & objects on the other side appear fuzzy/unclear

19
Q

What does opaque mean?

A

NO light passes through

light is either reflected or absorbed (converted to thermal EQ)

20
Q

What does reflection mean?

A

abrupt change in direction

21
Q

What does absorption mean?

A

transfer of energy from a wave to the matter that it passes through it

22
Q

What does transmission mean?

A

light is able to pass through

transparent/translucent mediums

23
Q

What does scattering mean?

A

When a particle changes in direction as a result of collision with another particle

24
Q

Will the image from a point source or an extended source be sharper?

A

Point source