Name... Form... SCIENCE YEAR 8 REVISION GUIDE PHYSICS SECTION

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1 Name... Form... SCIENCE YEAR 8 REVISION GUIDE PHYSICS SECTION

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3 Science Department This Revision Guide will be generated as the year progresses. Each topic is covered with both key fact sheets, a question sheet and a 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. You will be given a set of sheets for each topic as you cover them in lessons. The revision sheets will help you to revise for the end of unit test and your school entrance exams at the end of year 8. You will be given one hard copy to store in this folder but replacements can be found online in the Student and Parent Portal section of the school website. You are allowed to print as many copies as you like for your own use. We hope that they will be useful. Good Luck The Science Department

4 Energy Types of Energy Energy can be found in several different forms or types. You need to remember 8! Strain (Elastic) Sound Chemical Kinetic ENERGY Light Gravitational Potential Heat Electrical Law of Conservation of Energy Microphone: Sound Electrical Fire: Chemical (wood) Heat + Light Skydiver: Gravitational Potential (In Plane) Kinetic (Falling)

5 Renewable and Non-Renewable Energy Sources Non-Renewable 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 + Light) Coal (Chemical Heat + Light) Gas (Chemical Heat + Light) 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. Renewable 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) 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. Convection Current Conduction transfers heat through solids. Convection transfers heat through convection currents in liquids and gases. Radiation can pass through a vacuum.

6 Possible Revision Method Create a Mnemonic An mnemonic is a made up rhyme to help you memorise lists of information. Mnemonic Energy Types 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 SCIENCE: Heat Transfers Answer(s) Question

7 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 BBQ fuel burns? 7. What energy transfers occur in a Hydroelectric Power plant? (more than those stated) 8. Name three types of fossil fuel. 9. Name three types of renewable energy source. 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? For extra info or help with revision use the following pages in the KS3 CGP The Study Guide Energy Transfers pg. 66 & 67 Heat Transfer pg. 68 Conservation of Energy pg. 69 Energy Resources pg. 70 Generating Electricity pg. 71

8 Light & Sound Light Part of the electromagnetic spectrum (Visible spectrum) Travels in strait lines Reflection Angle of incidence (i) = Angle of reflection (r) The angle of reflection and incidence are measured between the ray and the normal, not the ray and the reflective surface. 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. Dispersion White light consists of a combination of the different colours of the rainbow. White light must be refracted twice in 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.

9 Sound Made by vibrating matter Travels much slower than light (speed of sound in air is 330m/s) Frequency and Amplitude are two different measurements taken from sound Frequency The number of vibrations in one second. How high or low (pitch) the sound is high frequency equates a high pitch; a low frequency equates a low pitch. Stringed instrument: To change frequency shorten string, tighten string, make string thinner 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 Drum: To change frequency tighten skin, make skin thinner Amplitude Changes the volume of the sound Stringed Instrument: To change amplitude pluck strings harder. Drum: To change amplitude hit the skin harder. Sound travels in Waves Two types of wave: Transverse and Longitudinal The shorter the wavelength (see diagram below) the higher the frequency. These are graphs of sound waves sound waves themselves are longitudinal. 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.

10 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. Summary Topic: Light Refraction, Reflection and Dispersion Card No.

11 Questions If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 1. What is unusual 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 glass to air? 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 and refracted twice? 9. Draw 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. How do you change the frequency of sounds coming from a guitar? 15. How do you change the amplitude of sounds coming from a drum? 16. What is an echo and how can it be useful? 17. Does sound travel faster in water or iron? Why? For extra info or help with revision use the following pages in the KS3 CGP The Study Guide Light Waves pg. 87 Reflection and Refraction pg. 88 How We See pg. 89 Colour pg. 90 Sound pg. 91 Hearing pg. 92

12 Density, Pressure and Speed Calculations Density Mass per unit of volume Measured in g/cm 3 or kg/m 3 Density (g/cm 3 ) = Mass (g) / Volume (cm 3 ) D = M/V Mass (g) = Density (g/cm 3 ) x Volume (cm 3 ) M = D x V Volume (cm 3 ) = Mass (g) / Density (g/cm 3 ) V = M/D Pressure Force per unit of area Measured in N/m 2 or N/cm 2 Sometimes measured in Pascals. 1 pascal = 1N/m 2 Pressure (N/m 2 ) = Force (N) / Area (cm 2 ) P = F/A Force (N) = Pressure (N/cm 2 ) x Area (cm 2 ) F = P x A Area (cm 2 ) = Force (N) / Pressure (N/cm 2 ) A = F/P Speed Distance per unit of time Measured in m/s or km/h Speed (m/s) = Distance (m) / Time (s) S = D/T Distance (m) = Speed (m/s) x Time (s) D = S x T Time (s) = Distance (m) / Speed (m/s) T = D/S

13 Conversions Please be careful that you convert units appropriately and effectively. Remember the following: 1 metre = 100 cm 1 kilometre = 1000 m 1 m 2 = cm 2 1 m 3 = cm 3 1 litre = 1000 ml 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 3 calculations relating to Density. 3. Without looking on the previous page. Write the full word equations (with units) for all 3 calculations relating to Pressure. 4. Without looking on the previous page. Write the full word equations (with units) for all 3 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/cm 3? 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 1.4cm 2 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? For extra info or help with revision use the following pages in the KS3 CGP The Study Guide Speed pg. 77 Pressure pg. 84

14 Forces A force is an influence which causes an object to change speed, direction or shape. Types of Force Gravity Friction Air Resistance/ drag Upthrust Magnetic Also known as weight. A force that pulls objects towards the centre of the earth. A force which acts against things speeding up e.g. brakes cause friction to slow wheels down A force which slows objects down as they fall through air A force applied by liquids to floating objects The force of attraction or repulsion applied by magnets Forces are measured using a forcemeter Forces are measured in Newtons (N) Magnetism Force of attraction or repulsion between certain substances like iron or nickel. Magnetic field of a magnet surrounds the North and South Poles and can be calculated with plotting compasses and drawn as shown. Mass and Weight Mass is the amount of matter present. Measured in grams, kilograms (kg) Weight is the measure of the effect of gravity on mass. Measured in Newtons (N) Gravity changes depending on the size of the object. The bigger the object the stronger the gravitational force. Gravity is far less on the Moon than on Earth so an equal amount of mass will weight differently on the Moon than to Earth.

15 Balanced and Unbalanced Forces If forces are balanced no change in speed, direction or shape occur If forces are unbalanced a change in speed, direction or shape can occur Balanced book doesn t float or fall through table. Unbalanced Rocket thrust force needs to be stronger than the weight Hooke s Law Extension is proportional to load. Once a spring breaches elastic limit it doesn t follow Hooke s law. Springs in parallel result in half the extension (flatter line on graph) Springs in series result in double extension (steeper line on graph) single parallel Moments series Moments are turning effects They are the reason that it is easier to turn a spanner from the handle end or to open a door further away from the hinges. Different sized loads can be balanced either side of a pivot if the distance from the pivot is adjusted. Moment = Force x distance from pivot How to calculate moments?

16 Questions If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 1. What are the three effects a force can have on an object? 2. Name three types of force. 3. How can you identify the magnetic field of an object? 4. What movement would you expect if the north pole of a magnet was pushed towards the North Pole of another magnet? 5. Does your mass change if you travel from the Earth to the Moon? 6. What is weight? 7. Give an example of balanced forces in action 8. Give an example of unbalanced forces in action 9. What is Hooke s law? 10. What is the name given to the point where a spring has stretched and does not follow Hooke s law? 11. What difference does have two springs joined end-to-end have to the amount of extension? 12. What is a moment? 13. How are moments calculated? 14. If Garfield weighs 200N and he is 2m from the pivot what is the moment generated on his side of the see-saw? 15. Are person A and B actually balanced (from previous page)? Do the calculations and see if the moments are equal. For extra info or help with revision use the following pages in the KS3 CGP The Study Guide Forces and Movement pg. 79 Friction and Resistance pg. 80 Force Diagrams pg. 81 Moments pg. 82 Forces and Elasticity pg. 83 Possible Revision Method Look, Write, Check Read the information on the topic. Write what you can recall. Check your work.

17 Electricity & Magnetism Current Electrical current is the flow of electrons around a complete circuit. Measured in Amps (A) Can generate a heating effect in resistance wire e.g. use in light bulbs. Circuit Symbols Drawing circuits must be done with the correct symbols. Make sure to remember the difference between series and parallel circuits. Logic Gates Parallel Series Logic gates consist of two switches which depending on the type of gate need to be either closed or open in the right order to result in an output. Learn the truth tables below! AND Gate Switch A Switch B On or Off Closed Open Off Open Closed Off Open Open Off Closed Closed On OR Gate Switch A Switch B On or Off Closed Open On Open Closed On Open Open Off Closed Closed On Current and Voltage Voltage is measured across a component. Components use the voltage up. Look at the diagram to see how a voltmeter is connected. Current is measured in series and does not get used up by components. What goes into the component always comes out. It only changes in a parallel circuit when the wires split the current.

18 Magnetism and Electromagnets Electromagnets are produced by coiling a wire around a soft metal core such as an iron nail. When a current is passed through a wire it generates a magnetic field Increasing strength of an Electromagnet Increase number of coils Increase strength of current Use an iron core. Using Electromagnets: Relays When switched on the electromagnet attracts the iron arm. When the arm moves it breaks the circuit and switches off the electromagnet thus creating a relay mechanism. Identifying the magnetic field Each bar magnet has a pole at each end, either North or South. Opposite pole attract each other. Like poles repel. Small compasses called plotting compasses can be placed near a bar magnet to show its magnetic field. To remember the direction of the arrows use the following mnemonic. N A S T Y North Away South Towards Yeah!!

19 Questions If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 1. What is current? 2. What effect can current have in a length of thin wire? 3. Draw the circuit symbol for a battery 4. Draw the circuit symbol for a variable resistor 5. Complete the following truth table for an AND gate. Switch A Switch B On or Off Closed Open Open Closed Open Closed Open Closed 6. Draw a basic parallel circuit with two lamps of equal brightness. 7. Describe differences between measuring current and voltage. 8. What must you do to a wire to produce an electromagnet? 9. Name two things that can be done to improve the strength of an electromagnet? 10. What happens when like poles of a bar magnet are pushed together? 11. What item of equipment can be used to draw the magnetic field of a bar magnet? 12. Which direction do compass arms point when identifying the magnetic field? N to S or S to N? For extra info or help with revision use the following pages in the KS3 CGP The Study Guide Electrical Circuits pg. 95 Measuring Current and Potential Difference pg. 96 Series and Parallel Circuits pg. 97 Static Electricity pg. 98 Magnets pg. 99 Electromagnets pg. 100 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 Create flash cards to learn key concepts/ key words in the topic of electricity Use blank paper following the previous templates.

20 Solar System and Astronomy Our Solar System Our Solar System consists of 1 star and 8 planets. Sun Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Helpful Mnemonic: My Very Eager Mother Just Served Us Nandos Star = Source of light and energy The Earth 1 Year = 1 compete orbit around the sun (365 days) 1 Day = 1 complete spin on its own axis (24 Hours) Day and Night Caused by spin of earth on its own axis Seasons Caused by tilt of earth s axis as it orbits the Sun. Seasons printed are for the northern hemisphere. What would the southern hemisphere seasons be?

21 The Moon A natural satellite Named a satellite because it orbits a planet Takes 28 days to orbit the earth. Eclipses The name of the eclipse is the thing that is being blocked out of view from Earth. Lunar Solar

22 Questions If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty. 1. List the planets of our solar system in order of distance from the Sun. Closest first. 2. How long does it take the Earth to orbit the Sun? 3. How long does it take the Earth to spin once on its axis? 4. What causes seasons? 5. What causes day and night? 6. Draw a diagram to represent why it is winter in the southern hemisphere when it is summer in the northern hemisphere. 7. Draw a diagram to represent a lunar eclipse 8. Draw a diagram to represent a solar eclipse 9. Why does the moon appear to change shape in the night s sky? 10. How long does it take the moon to orbit the Earth? For extra info or help with revision use the following pages in the KS3 CGP The Study Guide Gravity pg. 102 The Sun and Stars pg. 103 Day and Night and the Four Seasons pg. 104

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