Light

Question 0

Light conversion examples

Answer 0

Photosynthesis, solar cells, day-light timing on devices

Question 1

What is light?

Answer 1

Light is a form of energy

Question 2

How does light travel?

Answer 2

Light travels in straight lines

Question 3

Light and energy

Answer 3

Light is a way of transferring energy.

When an object absorbs light, the energy is transferred to heat and the object warms up a little.

Question 4

How does light travel? (eg. book)

Answer 4

Light from the lamp strikes the book.

Some of the light is reflected into our eye.

Question 5

To show that light travels in straight lines

Answer 5

Equipment:
3-4 pieces of card
a light source
your eyes

1) Put a hole in the exact same place on you pieces of card.
2) Line them up in a straight line against your light source.
3) Now make an un-even line. What happens?

Question 6

How fast does light travel?

Answer 6

Light travels at 300,000 km/s

Question 7

How much faster does light travel than sound? + Give an example

Answer 7

1 million times faster.
Light travels 340 m/s

Eg. thunder and lightning

Question 8

Transparent

Answer 8

See through it clearly

Question 9

Opaque

Answer 9

Prevents light through it

Question 10

Translucent

Answer 10

Allows some light through it

Question 11

Reflect

Answer 11

Sends the light back - does not absorb it

Question 12

Absorb

Answer 12

Takes something in

Question 13

Polychromatic

Answer 13

Produces light in all colours

Question 14

Shadows

Answer 14

Shadows are formed because light travels in straight lines

Light cannot pass through certain objects

A point source of life will give a dark shadow which is the same shape as the object

Question 15

Solar eclipse

Answer 15

A solar eclipse is formed when the moon blocks the light of the sun over the earth.

An eclipse will have a central dark area which will be due to no light reaching the earth from the sun.

It will have a outer, lighter area of shadow due to limited light from the sun.

Question 16

Luminous objects

Answer 16

Luminous objects make and give off their own light.

Eg. The sun, candle (due to chemical reaction), filament in a light bulb (the heated wire becomes white-hor giving off heat and light)

Question 17

Non-luminous objects

Answer 17

Do not make their own light, they reflect light from another source.

Eg, books reflecting light from the sun outside or the electrical lights.

Question 18

Examples of non-luminous objects

Answer 18

book
chair
table
mirrors
door

Question 19

Dispersion of light

Answer 19

Dispersion of light is the separating of light into its different colours.

Question 20

Order of the rainbow

Answer 20

red
orange
yellow
green
blue
indigo
violet

Question 21

Mirror writing

Answer 21

Mirror writing is laterally inverted so that you can read it properly in the mirror

Question 22

Convex/converging lenses

Answer 22

A lens that bends the light into a point

Question 23

Concave/diverging lens

Answer 23

A lens that bends light outwards.

Question 24

Refraction of light

Answer 24

The bending of light as it passes from one medium to another.