chapter 5 (ray model of light)

Question 1

What is light that travels in straight line paths called?

Answer 1

Rays.

Question 2

What are all the properties of light?

Answer 2

Light travels in straight lines
Light cannot bend

Question 3

What is a luminous object?

Answer 3

A object that emits light on its on.

Question 4

What is a non-luminous object?

Answer 4

A object that do not emit its own light, and can only be seen in the presence of a light source.

Question 5

What is the process of a light ray bouncing off a surface called?

Answer 5

Reflection.

Question 6

How are we able to see objects that do not emit their own light?

Answer 6

Light rays from another light source bounce off the surface of the object, reflecting it into our eyes.

Question 7

What are the characteristics of the image made in a mirror?

Answer 7

1. Same size as the object
2. Upright
3. Virtual
4. Laterally inverted

Question 8

What is the meaning of “laterally inverted”?

Answer 8

It means that the left and right sides of a image are reversed.

Question 9

Will the distance between the object and the mirror be the same as the distance of the image made from the mirror to the mirror?

Answer 9

Yes.

Question 10

What are the parts of the ray model of light?

Answer 10

1. The normal
2. The incidence ray
3. The reflected ray
4. The angle of incidence
   5, The angle of reflection

Question 11

What is the normal in a ray model of light?

Answer 11

It is the line perpendicular to the surface at the point of incidence.

Question 12

What is the incident ray in the ray model of light?

Answer 12

It is the light ray hitting the surface.

Question 13

What is the reflected ray in the ray model of light?

Answer 13

It is the light ray travelling away from the reflective surface after bouncing off the surface.

Question 14

What is the angle of incidence in the ray model of light?

Answer 14

It is the angle between the incident ray and the normal.

Question 15

What is the angle of reflection?

Answer 15

It is the angle between the reflected ray and the normal.

Question 16

What is the law of reflection?

Answer 16

Angle of incidence = angle of reflection

Question 17

What are the three different types of mirrors?

Answer 17

1. Plane mirror
2. Convex mirror
3. Concave mirror

Question 18

Which direction does a convex mirror curve? What type of image does it create?

Answer 18

Outwards. It creates smaller images, virtual, upright, and diminished. It creates a wider field of vision.

Question 19

What direction do concave mirrors face? What kind of image do they produce?

Answer 19

They face inwards. They create bigger, enlarged and magnified images.

Question 20

What happens when parallel rays of light fall onto a smooth surface?

Answer 20

Each light ray is reflected in the same direction.

Question 21

What happens when parallel rays of light fall onto a non-smooth surface?

Answer 21

Each ray is reflected in a different direction.

Question 22

What is refraction?

Answer 22

Refraction is the bending of light at the boundary between two transparent materials (optical mediums) due to a change in the speed of light as it passes from one material into the other.

Question 23

What affects the speed of light that travels through the medium in refraction?

Answer 23

Optical density.

Question 24

What colours make up the rainbow?

Answer 24

Red, orange, yellow, green, blue, indigo violet (ROYGBIV)

Question 25

What colour in the rainbow bends the most and least?

Answer 25

Violet bends most, red bends the least.

Question 26

What is the splitting of white light into different colours called?

Answer 26

Dispersion.

Question 27

What can infrared technology help us with? What are its harmful effects?

Answer 27

Medical purposes like taking temperature (thermal cameras). Overexposure to infrared light can cause climate change.

Question 28

What can ultraviolet light do? What are its harmful effects?

Answer 28

UV sterilisation can disinfect things without using harmful chemicals or releasing harmful by-products. Overexposure to UV radiation can harm eyes and cause skin cancer.

Question 29

What are some harmful effects of visible light?

Answer 29

Chemical changes in some materials, light pollution (too much artificial light in the environment).