Visible light and the solar system

Question 1

What is the geocentric model

Answer 1

The sun moon planets and stars all orbited the earth
In perfect circles
It was created by the Ancient Greeks in the 1500s

Question 2

What is the heliocentric model

Answer 2

The earth and the planets all orbit the sun which is at the centre of the universe
It was introduced by Copernicus in 1543
The orbits are in elliptical shape not circles

Question 3

What were Galileos observations and what did they prove

Answer 3

In 1610 he was observing Jupiter using a telescope when he saw three stars in a line near the planet
When he looked again the next evening he saw the stars had moved in the wrong direction in the night sky
He soon realised that these objects weren’t stars but moons orbiting Jupiter
They showed not everything orbited the Earth which proved the geocentric model wrong

Question 4

How did early astronomers observe the universe

Answer 4

Using the naked eye
They could only see the objects that were hit and gave out lots of visible light
Naked eye observations are only really useful for mapping positions

Question 5

How do telescopes help us observe the atmosphere

Answer 5

They magnify images so more distant objects can be seen in more detail
We can see objects that are further away
And discover more about what the universe is made up of

Question 6

How do photographs help us observe the atmosphere

Answer 6

They can be taken using telescopes so you can zoom in and look closer
We can monitor objects by taking pictures of them at different times and compare them to share with others you can see faint objects by having a long exposure time

Question 7

What is wave length

Answer 7

The distance form the peak of one wave to the next

Question 8

What is frequency

Answer 8

How many complete waves pass a point per second
It is measured in hertz
1hz is one wave per second

Question 9

What is amplitude

Answer 9

The height of the wave from the mid line to the top of the wave

Question 10

What is speed of a wave

Answer 10

How fast the wave goes

Question 11

What do waves do

Answer 11

They transfer energy and information without transferring energy

Question 12

Speed of wave=

Answer 12

Frequency x wavelength

Question 13

What is a transverse wave

Answer 13

The vibrations are at 90 degrees to the direction of travel of the wave 
Light and other em waves
S waves
Waves on strings or springs 
Ripples on water

Question 14

What is longitudinal wave

Answer 14

The vibrations are in the same direction as the wave is travelling
Sound and ultrasound
P waves
Slinky spring when you push and pull the end

Question 15

What is reflections

Answer 15

When a wave hits a boundary between one medium and another some energy is reflected
The angle of incidence is the same as the angle of reflection

Question 16

What is refraction

Answer 16

When a wave crosses a boundary between two mediums it changes speed
When the boundary is denser it slows down
When the boundary is lighter it speeds up

Question 17

What is a real image

Answer 17

When light from an object comes together to form an image in a screen

Question 18

What is a virtual Image

Answer 18

When the light appears to be coming from a different place

This happens in a mirror and in a magnifying glass

Question 19

What Happens with a converging lens

Answer 19

They’re convex so cause parallel rays to move together
The axis passes through the middle of the lens
The focal point is where all of the rays meet
Each lens has a focal point before and after the lens

Question 20

How to draw a ray diagram for a converging lens

Answer 20

Draw a point from the top of the object to the lens parallel to the axis
Draw another ray from the top of the object through the axis
The first incident ray is refracted through the focal point
The point where the two rays meet is the top of the Image

Question 21

How can you find out the distance from the lens to the focal point

Answer 21

Clamp a lens at one end of the track
Clamp a piece of white card further down
Set it up near a window with the lens directed at a distant object
Move the card along the track until the image is focused then clamp when you have the best Image
Use a ruler to measure the distance between the card and lens

Question 22

How does a refracting telescope work

Answer 22

It has an eyepiece and an objective lens
The objective lens converges the rays
The rays of light from the objective go to the eyepiece and the lens spreads them out so the image is magnified and becomes virtual

Question 23

How does a concave mirror work

Answer 23

An incident ray parallel to the the axis will pass through the focal point when reflected
An incident ray passing through the focal point will be parallel to the axis when reflected

Question 24

How to draw a ray diagram for a concave mirror

Answer 24

Draw a ray from the top of the object to the mirror parallel to the axis
Draw another line from the top through the focal point to the mirror
The parallel incident ray is reflected brought the focal point
The other incident ray is reflected parallel to the axis
Where the two rays meet is the top of the Image

Question 25

How do reflecting telescopes work

Answer 25

A large concave mirror collects the parallel rays of light from the object
It reflects the light onto a smaller mirror in front of the larger mirrors focal point
The smaller mirror reflects the light through a hole in the big mirror and a real image is formed
A converging eye piece is used to magnify the image