Science Light

Question 1

At what speed does Light travel at in vacuum?

Answer 1

3.0x10 to the power of 8 m/s

Question 2

Does light travel faster than sound?

Answer 2

Yes

Question 3

What are the 2 laws of reflection?

Answer 3

The angle of incidence is equal to the angle of reflection. & The incident ray, the reflected ray and the normal at the point of incidence all lie on the same plane.

Question 4

What are the different types of reflections?

Answer 4

Regular (for smooth surfaces)
Diffused (for rough surfaces)

Question 5

What are some characteristics of images formed with plane mirrors?

Answer 5

Upright
Same size as object
Image appears as far behind the mirror as the object is in front of the mirror.
Virtual
Laterally Inverted

Question 6

Name the 2 types of mirrors.

Answer 6

Convex ( diminished images)
Concave ( magnified images)
Convex bends outward, concave bends inward

Question 7

What is refraction?

Answer 7

Refraction is the bending of light as it passes from one transparent material to another due to the difference in the speed of light in the 2 different media.

Question 8

Which one is optically denser? Water or Air?

Answer 8

Water, it slows down and bends towards the normal

Question 9

Which one is optically denser? Glass or Air?

Answer 9

Glass.

Question 10

What is dispersion?

Answer 10

Dispersion is the separation of white light into its spectrum of colours.

Question 11

What is the colour that is bent the most?

Answer 11

Violet

Question 12

What is the colour that is bent the least?

Answer 12

Red

Question 13

Light is the only type of (….) we can see

Answer 13

Electromagnetic radiation

Question 14

What are some applications of infared

Answer 14

used in thermal imaging cameras to screen people for fever

used in burglar alarms to detect the movement of objects even in complete darkness

Question 15

What are some applications of ultraviolet

Answer 15

exposure to small amount of UV radiation increases the production of vitamin D in our bodies

used to treat babies with jaundice

used to disinfect medical equipment, food and water

Question 16

Applications of Visible light

Answer 16

Plants use the energy from visible light to make sugar using CO2 and water through photosynthesis
allows us to carry out our daily activities

Question 17

Harmful Effects of Infared

Answer 17

excessive infared radiation contributes to climate change

Question 18

Harmful effects of ultraviolet

Answer 18

can harm our eyes and also cause skin cancer

Question 19

harmful effects of visible light

Answer 19

light pollution, can cause serious damage to book, documents, causing inks and colours to face