Handout 1.1 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Name the four basic properties of light.

A

Light is a form of energy.
Light can travel in empty space.
Light travels in straight lines.
Light travels at a very high speed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Give three examples that show that light is a form of energy.

A

Light can power calculators and cars. Plants need light energy to produce food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give an example that light can travel in empty space.

A

There is no matter in the space between the sun and the earth — it is a vacuum — but sunlight can still reach us.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Give four examples that show that light travels in straight lines.

A

The formation of shadows that look like their objects — shadows are areas in which there is no light
A “symphony of lights” staged in Victoria Harbour
The light passing through clouds
The light shining through a gap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name two applications of light based on how it travels in straight lines.

A

Detector at the finish line of a running track

Laser engraving for making ornaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Elaborate on how light travels at a very high speed.

A

The speed of light in air and vacuum is about 3x10⁸m/s.

Light travels at a lower speed in other media. For example, the speed of light in water is about 2.25x10⁸m/s.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Objects can be _______________________ or __________________________. No matter what the object is, there must be ___________________________________________________ so that we can see it

A

luminous objects, non-luminous objects.

light coming from the object and entering our eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name three luminous objects. Explain how we can see luminous objects.

A

The Sun, a burning candle and a light bulb that is turned on.
The light from a luminous object enters the observer’s eye so that we can see it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name three non-luminous objects. Explain how we can see non-luminous objects.

A

The blackboard, the Moon and a beaker.
Although non-luminous objects do not emit light on their own, we can still see them due to the reflection of light from luminous objects into our eyes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Scientists use ____________ to study the behaviour of light. One of the models is the ________________________, which is based on _____________________________________________________.

A

models, ray model, the property that light travels in straight lines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

To classify, ______________________ can be ________________________, ________________________ (________________________), ________________________ (________________________), and they are made up of _____________________ — _________________________________________. What are these formed with?

A

light beams, parallel, divergent, spreading out, convergent, getting narrower, light rays, very narrow light travelling in a straight line.
Light beams can be formed by a ray box; while light rays can be formed by a ray box and slit plate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

We can use ray diagrams to __________________________________________. We use a straight line to __________________________________________ and an arrow to __________________________________________.

A

represent the light emitted by light sources; represent the path of each light ray, represent the direction of travel of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When we view an object, _____________________________________. To simplify, we ____________________________________________________________________________________________________________. If we want to show the light rays from a large object, we can ________________________________________________________________________.

A

many light rays from it enter our eyes; use two light rays to represent the cone of rays entering our eyes from a certain point of the object; draw two cones of rays entering our eyes from both ends of the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

For a ____________ object, the light rays entering our eyes are ______________________.
For a ____________ object, the light rays entering our eyes become ________________________.
For a ________________________, its rays are _____________ as they enter our eyes. However light rays entering our eyes are never ________________________, just ______. An example is ________________________. Why?

A

near, divergent, far, almost parallel, point object at infinity, parallel; perfectly parallel, ~0°, the light rays from the Sun. This is because the distance between us and the object is always finite.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly