Everything

Question 1

Light

Answer 1

Light travels in straight lines. Theses are called rays.

They can be converging, diverging and parallel

Question 2

Evidence that light travels in straight lines

Answer 2

Pinhole camera 
Shadows 
Light streaming through trees
Light streaming through water droplets In clouds 
Light in a laser beam

Question 3

Pinhole camera

Answer 3

The image is inverted upside down and formed on screen

The phrase we use for light travelling in straight lines is rectilinear propagation

Question 4

What speed does light travel at

Answer 4

It travels at 300,000,000mls

Question 5

When are shadows cast

Answer 5

When an opaque object stops light from reaching an area.

Question 6

Reflection

Answer 6

The angle of incidence equals the angle of reflection.
This is the law of reflection
All angles are measured from the normal

Question 7

Where is the image on a plain mirror

Answer 7

The image is the same distance behind the mirror as the object is in front

Question 8

What is apparent depth

Answer 8

Our eye doesn’t know that the light has been refracted when it comes from water into air and so the brain thinks that it has originated from a point closer to the surface

Question 9

What is the penumbra and umbra

Answer 9

The penumbra is a larger or extended source there is still an umbra
There is an outer region on the screen where all the light can reach. Between is a ring shaped region , partial shadow called the penumbra it is DIM and SHARP.
The umbra is the darker main shadow

Question 10

What is a solar eclipse

Answer 10

Solar eclipses work like extended source diagrams

Question 11

What is dispersion

Answer 11

When we shine light into a prism we see the colours of the rainbow are displayed on the screen
These colours are ROYGBIV

Question 12

Why does a red ball look red

Answer 12

Because the ball aborbs all the colours of the spectrum except red and it is reflected into the eye

Question 13

When are sounds made

Answer 13

They are made when a object vibrates eg guitar strings, drum skins, vocal chords

Question 14

What are compressions and rarefractions

Answer 14

Compressions occur when the particles are closest together

Rarefractions occur when the aprticles are furthest apart

Question 15

Sound

Answer 15

Sound is a longitudinal wave. This means that the direction or vibration is in the same direction as the movement of the wave

Question 16

There is air inside a bell jar so sound can travel and be heard but what happens if the air is removed

Answer 16

The bell jar and the sound can’t be heard because there is no air inside the bell jar

Question 17

The particles in a solid are close together what does this mean

Answer 17

This means vibrations are more easily passed form particle to particle and so sound travels fastest in solids, slower in liquids and slowest in gases

Question 18

Why can sound not travel in a vacuum

Answer 18

Because there are no molecules to pass on the vibrations. Sound is called a mechanical wave

Question 19

What happens when sound waves hit a solid

Answer 19

They are reflected back from the surface this is called an echo

Question 20

What is the speed of sound in water

Answer 20

1500mls

Question 21

What is the sum for working out how far away something is on a ship

Answer 21

Is the ship sends out a wave and it’s gets back in 1 second then it took 0.55

Distance speed x time
1500 x 0.5 = 750m. Time = distance = 35
Speed

Question 22

What are sound waves an example of

Answer 22

Longitudinal waves, like other waves sound waves move energy sound. Sounds are caused by vibrations. The particles of medium vibrate in the direction of the wave. Sound cannot travel in a vacuum as there are no particles to carry the vibration

Question 23

What can humans hear

Answer 23

We can hear sound waves with the frequencies in 20HZ to 20KHZ

Question 24

The ear

Answer 24

The pina, the ear canal, the ear drum, the 3 small bones (stirrup, anvil and hammer), the throat tube connected to your throat and the cochlea(takes nerve messages to your brain).

Question 25

Pitches

Answer 25

Low pitch(long wave length) ~
High pitch(short wave length)
Short note
Same note but LOUDER

Question 26

Parts of ear and function

Answer 26

Eardrum- when sound waves reach the ear drum it vibrates
Ossicles- this consists of the three small bones. These bones help make vibrations larger
Oval window- this has a smaller are a than the eardrum and passes the bigger vibrations to the cochlea
Cochlea- this is snail shaped and is filled with liquid and sends vibrations to the brain

Question 27

Problem, cause and cure

Answer 27

Problem. Cause. Cure
Wax Overactive gland. Syringe in ear
Perforated eardrum. Very loud noises Small holes cure themselves large holes need skin graft
Earache. Infection. Antibiotics
Tinnitus. Regular loud noise. Avoid loud noises
Limited move,ent of ossicles. Age. Hearing aids

Question 28

What is a noise

Answer 28

It is a un wanted sound

Loud noise can do permanent damage to our ears. It significantly increases the risk of permanent hearing loss