year 7 REVISION Physics

Transcription

1 year 7 REVISION Physics

2 Science Department This Revision Guide can be utilised at home or on your ipad. This electronic book has been made as an additional aid in the revision process. Each topic has been covered with key fact pages, questions and suggested revision method. The question sheet is designed to test your revision of the key facts and see if the information has sunk in. Just answering the questions is not an effective revision method. Please note, that the material provided should be used in conjunction with the boys own classwork and CGP guides distributed in Year 5 and Year 6. We hope that they will be useful. Best of luck!

3 Passwords Some of the links associated with this electronic revision book require passwords to access the information. Please find the relevant information below. TWIG WORLD: username: Y7science password: science BrainPOP: username: dcpslondon password: brainpopuk echalk: username: dulwichprep password: se217aa

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5 year 7 REVISION Energy

6 TYPES OF ENERGY Energy can be found in several different forms or types. You need to remember 8!

7 CONSERVATION OF ENERGY Energy cannot be created nor destroyed, it can only be transferred from one form to another. This quote is hugely important! It tells us that Energy will only change from one type to another.

8 ENERGY TRANSFERS EXAMPLES: Microphone: Sound Electrical Fire: Chemical (wood) Heat + Light Skydiver: Gravitational Potential (in plane) Kinetic (Falling)

9 RENEWABLE AND NON-RENEWABLE ENERGY SOURCES NON-RENEWABLE RESOURCES An energy resource that will not be replenished in one s lifetime. Fossil Fuels are prime examples of non-renewable energy sources. Oil (Chemical Heat) Coal (Chemical Heat) Gas (Chemical Heat) All fossil fuels originally derived their energy from the sun when the organisms that formed them were alive. Fossil Fuels will run out. It takes millions of years for them to be made. They are all energy in the form of chemical energy.

10 RENEWABLE AND NON-RENEWABLE ENERGY SOURCES RENEWABLE RESOURCES An energy resource that will be replenished in one s lifetime. Sometimes more expensive to initiate but more kind on the environment Examples include: Solar (light electrical or heat), Wind (kinetic electrical), Tidal (kinetic Electrical), Hydroelectric (Kinetic Electrical)

11 THERMAL (HEAT) ENERGY Thermal energy is one of the most common forms of energy. It can transfer from one place to another in a variety of different ways.

12 POSSIBLE REVISION METHOD - CREATE A MNEMONIC An mnemonic is a made up rhyme to help you memorise lists of information.

13 POSSIBLE REVISION METHOD - REVIEW CARDS (FLASH CARDS) Review Cards pose questions with long answers or facts on the back. Flash Cards can be used to learn key words or definitions

14 QUESTIONS If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 1. Name eight different types of energy. 2. Which type of energy is gained when you climb a ladder? 3. Which type of energy is stored in our food? 4. What is the law of conservation of energy? 5. What energy transfer occurs in a guitar amplifier? 6. What energy transfer occurs when you light BBQ fuel? 7. What energy transfers occur in a hydroelectric power plant? (More than those stated) 8. Name three types of fossil fuels

15 QUESTIONS If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 9. Name three types of renewable energy sources. 10. What is a drawback of renewable energy? 11. What is a positive of renewable energy? 12. Why are fossil fuels not a good source of energy for the future? 13. Name the three methods by which thermal energy can be transferred. 14. What happens to heat energy during convection? 15. How do radiators heat a room effectively? 16. Is radiator a good name for a radiator?

16 For extra information or help with revision use the following pages in the KS3 CGP Study Guide, pages

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18 year 7 REVISION Light and Sound

19 LIGHT Part of the electromagnetic spectrum (visible spectrum) Travels in straight lines

20 REFLECTION Angle of incidence (i) = Angle of reflection (r) Only true when reflecting off a plane mirror!

21 REFLECTION Position of reflected image in mirror

22 REFRACTION Refraction is when light changes direction due to a change of speed as it enters from one medium to another. When light slows down it moves towards the normal. When light speeds up it moves away from the normal. The normal is drawn perpendicular (at right angles) to the surface of the new medium.

23 DISPERSION White light consists of a combination of the different colours of the rainbow. White light must travel through a prism to disperse into its different colours (the spectrum). Diagrams: You should be able to draw basic diagrams of Reflection, Refraction and Dispersion. Knowing how to draw them should help you remember how the light is affected and how it moves.

24 SOUND Made by vibrating matter Travels much slower than light (speed of sound is 330m/s) Frequency and Amplitude are two different measurements taken from sound Echoes: occur when sound reflects of a surface and travels back to where it was made. Used to measure distances. For example, sonar or echolocation

25 FREQUENCY The speed at which the matter is vibrating. How high or low (pitch) the sound is. Stringed instrument: To increase frequency shorten string, tighten string, make string thinner Drum: To increase frequency tighten skin, make skin thinner

26 AMPLITUDE The volume of the sound Stringed Instrument: To increase amplitude pluck strings harder. Drum: To increase amplitude hit the skin harder.

27 SOUND TRAVELS IN WAVES Two types of wave: Transverse and Longitudinal. The shorter the wavelength (see diagram below) the higher the frequency.

28 SOUND TRAVELLING THROUGH DIFFERENT MEDIUMS Light travels faster through solids than liquids and gases. This is because the particles are closer together and thus pass vibration on more efficiently.

29 POSSIBLE REVISION METHOD - AUDIO For auditory learners, try reading the information aloud, record yourself reciting key facts, use video clips, put key facts into a well known tune or talk about your learning to others. POSSIBLE REVISION METHOD - SUMMARY CARDS Summary Cards contain the most important details of a topic. You should try to create a summary of the information, including key words, concepts and diagrams.

30 QUESTIONS If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 1. What is special about how light travels? 2. Does light travel faster or slower than sound in air? 3. When light rays hit a mirror what process do they undergo? 4. What is the relationship between the angle of incidence and the angle of reflection? 5. Where do you draw the normal on a light ray diagram? 6. What happens when light travels from one medium (air) to another (glass)? 7. If light slows down when travelling from one medium to another does it bend towards or away from the normal? 8. What happens when light rays are shone through a prism at the correct angle?

31 QUESTIONS If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 9. Draw the diagrams of Reflection, Refraction and Dispersion. 10. What is it that makes sound? 11. What is frequency? 12. What is amplitude? 13. What is the relationship between wavelength and frequency? 14. What are the two types of sound wave? 15. How do you change the frequency of sounds coming from a drum? 16. How do you change the amplitude of sounds coming from a guitar? 17. What is an echo and how can it be useful? 18. Does sound travel faster in water or iron? Explain your reasoning!

32 For extra information or help with revision use the following pages in the KS3 CGP Study Guide, pages

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34 year 7 REVISION Speed, Density & Pressure

35 SPEED Distance per unit of time Measured in m/s or km/h formulae d speed (m/s) = distance (m) / time (s) distance (m) = speed (m/s) x time (s) s t time (s) = distance (m) / speed (m/s)

36 DENSITY Mass per unit of volume Measured in g/cm³ or kg/m³ formulae m Density (g/cm³) = mass (g) / volume (cm³) mass (g) = Density (g/cm³) x volume (cm³) D v volume (cm³) = mass (g) / Density (g/cm³)

37 PRESSURE Force per unit of area Measured in N/m² or N/cm² Sometimes measured in Pascals, 1 Pascal = 1N/m² formulae F Pressure (N/m²) = Force (N) / Area (m²) Force (N) = Pressure (N/m²) x Area (m²) P A Area (m²) = Force (N) / Pressure (N/m²)

38 CONVERSIONS Please be careful that you convert units appropriately and effectively. Remember the following: 1 metre = 100 cm 1 kilometre = 1,000 m 1 m² = 10,000 cm² 1 m³ = 1,000,000 cm³ 1 litre = 1,000 ml

39 QUESTIONS If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 1. What is a more unusual unit used for pressure? 2. Without looking on the previous page. Write the full word equations (with units) for all three calculations relating to Density. 3. Without looking on the previous page. Write the full word equations (with units) for all three calculations relating to Pressure. 4. Without looking on the previous page. Write the full word equations (with units) for all three calculations relating to Speed. 5. How many metres in 1.53 km? 6. How many litres is 897ml? 7. How many metres is 1240cm? 8. What is the volume of a stone that has a mass of 120g and a density of 4g/cm³?

40 QUESTIONS If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 9. Mo Farah took 13mins 40s to complete the 5000m race at the London 2012 Olympics. How fast was he running on average? 10. How much pressure does the stiletto with an area of 1.4cm² exert on the floor when a woman weighing 500N stands on one leg? 11. What is the density of grandma s fruit cake? It is a cuboid shape with a height of 10cm, width of 15cm and length of 30cm and when placed on the scales measures in at 1kg. 12. Yohan Blake was clocked running 100m in training at an average of 40km/h. Would he beat Usain Bolt s 100m World record of 9.58s?

41 For extra information or help with revision use the following pages in the KS3 CGP Study Guide, pages 77 & 84.