1. P1 Revision
Mr Sellars

2. Areas Covered Refracting and Reflecting Telescopes EM Spectrum
Life Cycle of a Star
Big Bang and Red Shift
Seismic Waves

3. Telescopes
Telescopes use light to look at far away objects in close detail
They do this by bending light and changing the focal point of that light
There are 2 types you need to know about Refracting and Reflecting Telescopes

4. Refracting Telescopes
Exam Tip
Remember you must draw ray diagrams with a ruler and show the direction of the light with an arrow

5. Reflecting Telescope Exam Tip
Remember you must draw ray diagrams with a ruler and show the direction of the light with an arrow

6. Exam Questions
Complete the ray diagram for a refracting telescope

7. EM Spectrum
Exam Tip
You may be asked to give the EM Spectrum from Radio to Gamma waves or Gamma to Radio Waves
Read the question carefully

8. Use of the EM Spectrum Exam Tip
Do not say Microwaves are used in Microwaves or to cook food
You must say Microwave Ovens!
EM Wave
Use
Radio Waves
TV and Radio Communication
Micro
Waves
Microwave Ovens
Mobile Phones
Satellite communication
Sky TV
Infrared (IR)
TV Remotes
Thermal Imaging cameras
Visible Light
Eyes
Cameras
Ultraviolet (UV)
Sun beds
Security pens
X-Rays
X Rays to look at bones
Gamma
Kill cancer cells
Kill bacteria on soft fruit

9. EM Spectrum
Least
Dangerous
Most
Dangerous

10. EM Spectrum Exam Questions
Wave speed/frequency = wavelength
/ = wavelength
0.6
Exam Tip
If you did not convert the kHz you would drop 1 mark

11. Life Cycle of a Star

12. Small Star (like our sun)
Stars Stages
What is Happening in Each Stage
Nebular
A cloud of dust and gas, being brought together by gravity – all the building blocks for a star
Protostar
Gas cloud is now more densely packed, this starts to get everything very hot
Main Sequence
Star is fuelled by the fusion of Hydrogen atoms to form Helium atoms.
Force of gravity pulling in is balanced with the outward force from the fusion
Red Giant
Star has run out of Hydrogen atoms to fuse together, has to fuse together larger atoms.
Forces are unbalanced so star grows bigger
White Dwarf
Outer layers have broken away leaving the white hot core
Black Dwarf
Over time the white dwarf cools to form this

13. Large Star Stars Stages What is Happening in Each Stage Nebular
As before
Protostar
As Before
Main Sequence
As Before but much quicker
Red Super Giant
Star has run out of Hydrogen atoms to fuse together, has to fuse together larger atoms.
Forces are unbalanced so star grows bigger
Super Nova
The star explodes throwing out all the elements that have been made inside it
Black Hole or
A point of infinate density, all the matter inside the star is crushed to a point smaller than an atom
Gravity is so strong not even light can escape
Neutron Star
A core left behind from the super Nover made up of only neutrons, this gives out bursts of radio waves that can be detected on earth
Brian Cox Video: Life Cycle of a star

14. Factors that effect the life cycle of a star
How much hydrogen it has
The more hydrogen the star has the longer it will stay in its main sequence for
The mass of the Star
The larger the mass of the star, the faster it will use up the hydrogen so main sequence will not last as long.
This also decides if the star will turn into a Red Giant or a Red Super Giant

15. Life Cycle of a Star Exam Questions
Exam Tip
If this is a longer answer question, you can draw the diagram if it helps you!
Life Cycle of a Star Exam Questions
Dust and gas are pulled together by gravity 2 2
When there is enough mass nuclear fusion
Will start

16. Life Cycle of a Star Exam Questions
Red Giant
White Dwarf
Black Dwarf

17. Doppler Effect
Doppler Effect Video

18. Red Shift

19. Red Shift
Red Shift
Blue Shift

20. Big Bang

21. E f C B D A

22. Cosmic Microwave Background Radiation (CMB)

23. Evidence for the Big Bang Theory
Red Shift – All stars show signs of Red Shift, this means they must be moving away from each other
The stars furthest away have the biggest Red Shift
CMB the only explanation for this is that it is the left over radiation from the Big Bang

24. C

25. Seismic Waves (P and S Waves)
In an earth quake there are 2 types of waves given off P and S waves
P Waves
these area the first to reach a detector
The are longitudinal waves
They can travel through liquid and solid parts of the earth
S Waves
These arrive second
They can only travel through the solid part of the earth so are stopped by the liquid core

26. 5 waves in 10 seconds
5/10 = 0.5