P1 Physics Essential Questions

Transcription

1 P1 Physics Essential Questions Particles and Kinetic Theory Name. Solid, liquid and gas are three different states of matter. Describe the difference between the solid and gas states, in terms of the arrangement and movement of their particles. According to kinetic theory, all matter is made up of small particles. The particles are constantly moving. One kilogram of a gas has a much larger volume than one kilogram of a solid. Use kinetic theory to explain why. Diagram 2 shows the particles in a liquid. The liquid is evaporating. Diagram 2 How can you tell from Diagram 2 that the liquid is evaporating? The temperature of the liquid in the container decreases as the liquid evaporates. Use kinetic theory to explain why. (3)

2 Infrared Radiation The diagram shows a car radiator. The radiator is part of the engine cooling system. Liquid coolant, heated by the car engine, enters the radiator. As the coolant passes through the radiator, the radiator transfers energy to the surroundings and the temperature of the coolant falls. Why is the radiator painted black? The diagram shows a simple type of portable shower. The water container is a strong plastic bag that is black on one side and white on the other. To warm the water, the bag is placed on the ground in direct sunlight, with the black side facing the Sun. Name the process by which heat is transferred from the Sun to the outside of the bag.... Explain why the black side of the bag and not the white side should face the Sun. The diagram shows a fridge-freezer. The outside surface of the fridge-freezer is white and shiny. Give two reasons why this type of surface is suitable for a fridge-freezer

3 Convection The figure below shows a fridge with a freezer compartment. The temperature of the air inside the freezer compartment is 5 C. The air inside the fridge forms a convection current when the fridge door is closed. Explain why An electric immersion heater is used to heat the water in a domestic hot water tank. When the immersion heater is switched on the water at the bottom of the tank gets hot. Energy is transferred by the process of convection from the hot water at the bottom of the tank to the cooler water at the top. Explain how The diagram shows potatoes being baked in a gas oven. Each potato has a metal skewer pushed through it. Explain how heat is transferred by the process of convection from the gas flame at the bottom of the oven to the potatoes at the top of the oven (3)

4 Conduction The diagram shows the position of a radiator inside a room. The radiator is made from metal and is painted white. Heat is transferred from the hot water inside the metal radiator to the air touching the outside surface of the radiator. What name is given to this method of heat transfer?... Explain, in terms of the particles in the metal, how heat is transferred through the radiator The diagram shows a metal pan being used to heat water. Energy from the gas flame is transferred through the metal pan by conduction. Explain the process of conduction through metals....,,,,,,,,......,,,,,,,, The image shows a can-chiller. Energy is transferred through the metal walls of the can of drink by conduction. Explain how

5 Insulating Buildings A householder wants to reduce her energy bills. She collected information about a number of ways of reducing energy used. The information is shown in the table. Ways of reducing energy used Cost to buy and install in Money saved per year in Install an energy-efficient boiler Insulate the loft Install double-glazed windows Install cavity wall insulation Use the information in the table to compare the different ways of reducing the energy used. Your answer should include some calculations. Increasing the amount of insulation in a house affects the total U-value of the house. What is meant by the term U-value? (6) How is the U-value affected by increasing the amount of insulation? A homeowner pays 7600 to have solar panels fitted on the roof of their house. The homeowner expects to save 950 each year from reduced energy bills and from selling the electricity. Assuming these figures to be correct, calculate the pay-back time for the solar panels. Show clearly how you work out your answer. Pay-back time =... years

6 Between 2002 and 2008 the amount of electricity used for lighting in homes in the UK decreased. Suggest one reason why. Explain why using an energy-efficient light bulb instead of an ordinary light bulb reduces the amount of carbon dioxide emitted into the atmosphere. Evaporation Explain, in terms of particles, how evaporation causes the cooling of water. When a person uses the shower the mirror gets misty. Why? (3)

7 Energy and Efficiency Use words from the box to complete each of the following sentences. chemical electrical light sound The solar cells transfer light energy to... energy. The batteries transfer... energy to electrical energy. The LEDs transfer electrical energy to... energy. An electric motor is designed to transform electrical energy into... energy. Some of the electrical energy supplied to the motor is wasted as... energy and... energy. What happens to the energy wasted by the electric motor? (3) The Sankey diagrams show the energy transfers in a traditional coal-burning power station and a combined heat and power (CHP) station. Waste energy Waste energy What effect does the waste energy from a power station have on the surroundings? Calculate the efficiency of the CHP station. Use the correct equation from the Equations Sheet. Why is a CHP station more efficient than a traditional coal-burning power station?

8 Generating Electricity Non-Renewable Source: Fossil Fuels Describe, in as much detail as you can, how the energy stored in coal is transferred into electrical energy in a power station. About half of the UK s electricity is generated in coal-burning power stations and nuclear power stations. Coal-burning power stations and nuclear power stations provide a reliable way of generating electricity. What is meant by a reliable way of generating electricity? (5) In the UK, most electricity is generated in power stations that burn fossil fuels. Which type of fossil fuel power station has the shortest start-up time? In the UK, over 70% of the electricity is generated in power stations that burn fossil fuels. Explain one effect that burning fossil fuels has on the environment. Give one way the effect on the environment described could be reduced. Assume the amount of fossil fuels burnt stays the same.

9 Non-Renewable Source: Nuclear In the UK, nuclear fuels are used to generate about 21% of the total electricity supply. What is the name of the process by which a nuclear fuel produces heat?... Explain how the heat released from a nuclear fuel is used to generate electricity in power stations. Some people have suggested that more nuclear power stations should be built in the UK. Give two reasons to support this suggestion Nuclear power stations create dangerous waste. Why is the waste from a nuclear power station dangerous? What does it mean to decommission a nuclear power station? How does decommissioning affect the overall cost of electricity generated using nuclear fuels? Renewable Source: Geothermal What is meant by an energy source being renewable? What is geothermal energy?

10 Renewable Energy: Hydroelectric: In 2013, about 80% of Iceland s electricity was generated using hydroelectric power stations (HEP). Describe how electricity is generated in a hydroelectric power station. Include the useful energy transfers taking place. A pumped storage hydroelectric system can also be used as a way of storing energy for future use. Explain how. (6) An advantage of pumped storage hydroelectric power stations is the short start-up time they have. What is the importance of the short start-up time? Give one other advantage of a pumped storage hydroelectric power station. Renewable Energy: Solar Solar panels are often seen on the roofs of houses. Describe the action and purpose of a solar panel.

11 National Grid What is the National Grid?..... The diagram shows the National Grid system. Similar questions: Transformers X and Y are an essential part of the National Grid system. Explain why. How is the National Grid designed to reduce energy losses during transmission? The National Grid includes step-up transformers. Explain why. The voltage across the overhead cables of the National Grid needs to be much higher than the output voltage from the power station generators. Explain why New cables in the National Grid will be suspended from pylons and run overhead while the rest will be buried underground. Outline the advantages and disadvantages of both overhead transmission cables and underground transmission cables (6)

12 Properties of Waves Complete the sentence: Waves transfer. The diagram shows a wave pattern. Which letter, L, M or N shows: the wavelength?... the amplitude?... Waves may be longitudinal or transverse. Describe the differences between longitudinal waves and transverse waves Name one type of wave that may be either transverse or longitudinal... Radio waves are electromagnetic waves. Describe how radio waves are different from sound waves. (3) Oscilloscopes A microphone and a cathode ray oscilloscope (CRO) can be used to show the pattern of a sound wave. Four sound wave patterns, A, B, C and D, are shown. They are all drawn to the same scale. (a) Which one of the patterns has the smallest amplitude?... (b) Which one of the patterns has the lowest frequency?... (Total 2 marks)

13 Waves for Communication Basic Questions Radio waves, microwaves and visible light are all electromagnetic waves that are used for communication. Name another electromagnetic wave that is used for communication.... Name an electromagnetic wave which is not used for communication. State a use for this electromagnetic wave. Electromagnetic wave... Use... Visible light is part of the electromagnetic spectrum. This shows part of the electromagnetic spectrum. Infrared Visible Ultraviolet Three of the colours of visible light are green, red and violet. Place these colours in order of increasing wavelength.... Smallest wavelength Largest wavelength Use the correct answers from the box to complete the sentence. decreases stays the same increases As the frequency of the light waves increases, the wavelength of the light waves... and the energy of the light waves.... The diagram below shows six of the seven types of wave that make up the electromagnetic spectrum. Gamma rays Ultraviolet Visible light Infrared Microwaves Radio waves What type of electromagnetic wave is missing from the diagram?... Which of the following electromagnetic waves has the most energy? Draw a ring around the correct answer. gamma rays radio waves visible light Draw a ring around the correct answer in the box to complete the sentence. a slower speed than Microwaves travel through a vacuum at the same speed as radio waves. a faster speed than

14 Draw a ring around the correct answer to complete the sentence. The range of wavelengths for waves in the electromagnetic spectrum is approximately to to to metres. State one hazard of exposure to infrared radiation... State one hazard of exposure to ultraviolet radiation... X-rays are used in hospitals for computed tomography (CT) scans. State one other medical use for X-rays..... State a property of X-rays that makes them suitable for your answer in part (d)(i)..... Reflection A person can see an image of himself in a tall plane mirror. The diagram shows how the person can see his hat. Which point, A, B or C, shows the position of the image of his hat?.. On the diagram, use a ruler to draw a light ray to show how the person can see his shoe. Which one of the words in the box is used to describe the image formed by a plane mirror? (3) imaginary real virtual What is a plane mirror?...

15 Refraction Light can be made to change direction as it passes into and out from a block of glass. Complete the ray diagram below. Diffraction The diagram shows water waves in a ripple tank moving towards a gap in a barrier. The water waves diffract as they pass through the gap. Complete the diagram to show the diffracted water waves.

16 Sound Diagram 1 shows a longitudinal wave being produced in a stretched spring. A longitudinal wave has areas of compression and areas of rarefaction. Mark with the letter C, one area of compression shown in Diagram 1. What is a reflected sound called? There is no air in space. Astronauts in space cannot hear sounds from outside their spacesuits. Explain this. A microphone is connected to a cathode ray oscilloscope (CRO) being used to detect the note produced by the keyboard. Figure 2 shows the trace produced by the sound wave on the CRO. A second note, of different wavelength, was played on the keyboard. Figure 3 shows the trace produced by the sound wave of the second note on the CRO. The settings on the CRO were unchanged. What two conclusions should be made about the second sound wave produced by the keyboard compared with the first sound wave? Give a reason for each conclusion. Conclusion 1... Conclusion 2... Doppler Effect 1. What is the Doppler effect?

17 Red Shift The Big Bang theory is one theory of the origin of the Universe. 1. Explain what is meant by the Big Bang theory. 2. The light from distant galaxies shows a red-shift. What is red-shift? 3. How does the red-shift from distant galaxies provide evidence for the beginning of the Universe? Cosmic microwave background radiation (CMBR) is a type of electromagnetic radiation. CMBR fills the Universe. It was first discovered in 1965 by two astronomers called Penzias and Wilson. 4. What do scientists believe is the origin of CMBR?. 5. Why was the discovery of CMBR so important to the scientists believing the Big Bang theory to be correct? (3) 6. How is the wavelength of CMBR likely to change, if at all, over the next billion years? Give a reason for your answer. 7. Scientists can answer many questions about the universe, but not the question: Why was the universe created? Suggest a reason why this question cannot be answered by scientists.

18 Calculations wave speed = frequency wavelength v = f λ wave speed =distance time cost of electricity = power time cost of 1 kilowatt-hour power = energy used time taken efficiency = (useful energy transferred) (total energy supplied 1. A water wave has a wavelength of 8m and a frequency of 4.5Hz. What is its wavespeed? 2. A wave on the sea travels at 5m/s and has a wavelength of 6m. What is its frequency? 3. Radio 1 is a frequency of 97MHz (97 x 10 6 Hz) and it travels at the speed of light which is 3 x 10 8 m/s. What is its wavelength? 4. A gamma wave has a wavelength of 6 x 10-8 m and it travels at the speed of light (3 x 10 8 m/s). What is its frequency? 5. A wave travels 35m in 7 seconds. What is its speed? 6. A wave travels at 2.9km/s for 3minutes. How far does it travel in metres? 7. How long does it take a wave travelling at 3cm/s to travel a distance of 9.6m? Power must be measured in KILOWATTS (kw). Time must be measured in HOURS. 8. A 2kW fire is on for 6 hours & 1 kilowatt-hour costs 12p. How much does the electricity cost? 9. A 150W T.V is on for 13 hours & 1 kilowatt-hour costs 12p. How much does the electricity cost? 10. A 700W hairdryer is on for 8 minutes and 1 kilowatt-hour costs 15p. How much does the electricity cost? 11. A 50W fridge is on for 5 days and 1 kilowatt-hour costs 9p. How much does the electricity cost? 12. A lawnmower uses 5000J of energy in 32s. What is its power? 13. A toaster has a power of 350W and is on for 2 minutes. How much energy does it use 14. How long does a 5kW car engine take to use 6 MJ (6 x 10 6 J) of energy? 15. A motor bike is 30% efficient. If the total energy supplied to it is 6000J, how much energy is usefully transferred to it? X 100% Energy Change = mass x temperature change x specific heat capacity 16. A kettle uses 160kJ of energy to heat the water in it from 25 C to 100 C. How much water is in the kettle in kg? 17. A chemist uses a Bunsen burner to heat some ethanol in a beaker. If the energy input is 2.5kJ and the temperature change is 21 C to 32 C, find the mass of ethanol that was heated in kg. 18. A spinning bicycle wheel needs to be brought to a stop by a rubber brake block. Assuming the wheel has 500J of kinetic energy that is all absorbed by the brake and that the mass of the block is 25g, how much will the temperature of the block rise by in C? 19. A convection heater is used to heat the air in a house. If it is on for 15 minutes and transfers 2000kJ of heat energy to the air, find the increase in temperature of the air in C if there is 124kg of air in the room. 20. An electrical circuit malfunctions and starts to overheat. The copper wire of the circuit has a mass of 3g and it increases in temperature from 20 C to 60 C. How much energy is transferred to the wire in joules?