| What are the nine energy stores? | The nine energy stores are LSG Cenek, or Light, Sound, Gravitational potential energy, Chemical, Electrical, Nuclear, Elastic potential energy, and Kinetic |
| What is elastic potential energy? | Elastic potential energy is energy stored as a result of applying a force to stretch an elastic object |
| What is extension in a spring? | Extension in a spring is when it stretches from an applied force. |
| How can the elastic potential energy stored in a spring be increased? | The elastic potential energy stored in the spring can be increased by the force stretching or compressing the spring which does work on the spring. |
| When is the extension is directly proportional to the force? | The extension is directly proportional to the force when the straight line of the extension against the force applied graph goes through zero. However, if a greater force is applied, the extension will no longer be directly proportional to the force because the spring has been stretched beyond its limit of proportionality so it won’t be able to return to its original length if the force is removed |
| What's the equation for elastic potential energy? | Ee = 0.5 x k x e^2
elastic potential energy (J) = 0.5 x spring constant measured (nm) x extension (m) |
| What is gravitational potential energy? | Gravitational potential energy is the energy stored in an object due to its position above the Earth’s surface, which is due to the force of gravity acting on the object |
| What is the equation for Gravitational potential energy? | Ep = m x g x h
Gravitational potential (J) = mass (kg) x gravitational field strength (n/kg) x height (m) |
| What is specific heat capacity? | The Specific heat capacity of a substances is the amount of energy required to raise the temperate of 1kg of the substance by 1 degree celsius |
| What is the specific heat energy equation? | E = m x c x 0 (theta)
Change in thermal energy (J) = mass (kg) x specific heat capacity (J/Kg degree Celsius) x temperate change (degree celsius) |
| What is an energy system? | An energy system is an object or group of objects, and closed energy systems cannot lose matter or energy |
| What is the principle of conservation of energy? | The principle of conservation of energy is energy can only be transferred to another form of energy or dissipated to the surroundings, it cannot be created or destroyed |
| What is the equation for work done? | Work done (J) = Force (N) x Distance (m) |
| What is work? | Work is the energy transferred to or from an object when an application of force is placed along a displacement |
| How much work needs to be done to bring an object back to the earth’s surface? | When an object is thrown work is done against the force of gravity, so it gains gravitational potential energy, and it will need the same amount of work done would have to be exerted by the force of gravity to bring it back to the earth’s surface. |
| What is power? | Power is the rate at which energy is transferred or work is done |
| What are the equations for power? | Power (Watts) = energy (J)/time (s)
but the equation for electrical power is Power (W) = Current (A) x Voltage (V) |
| What are the efficiency equations? | Efficiency = useful output energy transfer/ total input energy transfer
Efficiency = useful power output / total power input |
| How do you know if you have incorrectly calculated efficiency and how can the efficiency be calculated as a percentage? | Keep in mind that any answer above 1 which is virtually impossible for this equation and therefore if you do have a value above 1 as your answer, you have most likely divided the input by the output instead of the output by the input.
And changing the original decimal answer into a percentage is done by multiplying the decimal by 100 |
| What are the issues with heating water in a pan, and how can they be solved? | When water is heated in a pan thermal energy can be lost as it can pass into the air at the water’s surface and around the edges of the hob, thermal energy can be more directly passed from the hob into the water by using a pan with a wider base and a lid.
Secondly, when water is heated in a pan, thermal energy can be used to heat the base of the pan alone. To prevent this the heating element can be placed inside the water, which is how an electrical kettle works |
| What are the advantages of heating water in a kettle? | The advantage of heating water in a kettle is less thermal energy passes from the walls and the lid of the kettle, into the air. This is because kettles are made of plastic; a less successful heat conductor than metal; making water have lower thermal conductivity, therefore kettles are more efficient for heating water than pans which are usually made from metal; an efficient heat conductor, that enables heat to pass through the pan's sides and lid, and into the air. |
| What is the effect of thermal conductivity on energy? | The higher the thermal conductivity of a materials the higher the rate of energy transfer by conduction across that material. |
| What is the thermal conductivity of modern houses in terms of brickwork, and how can is it tackled? | Modern houses are built from two layers: an external brick wall and an internal breezeblock wall, between the walls, is a cavity and the thermal conductivity of walls built like this is fairly high therefore a lot of thermal energy can transfer out the house.
To tackle this issue, builders pack the cavity with an insulating material that has a very low thermal conductivity, which reduces the overall thermal conductivity escaping the house |
| What is the thermal conductivity of modern houses in terms of glass work, and how can is it tackled? | In houses thermal energy can escape from the windows. Single glazed windows have high thermal conductivity, so most house have double glazed windows, which have a lower thermal conductivity so less thermal energy can exit the house |
| What is the specific heat capacity for copper, aluminium, and gold? | The specific heat capacity for copper is 385J/Kg degrees C, for aluminium it is 913 J/Kg degrees C, and for Gold, it is 126J/kg degrees C. |
| What do you do before the specific heat capacity practical? | Before the specific heat capacity practical, put a heater in the aluminium block and in the smaller hole put a thermometer and a few drops of water to ensure accurate readings. |
| How is the specific heat capacity practical done? | In the specific heat capacity practical take a reading of the initial temperature, then turn the power supply and stop-clock at the same time.
Now find the power by counting the number of flashes on a joule meter per second and multiplying that by 100, although because this power can get lost when it goes into the heater the power can also be measured with a voltmeter.
To do this put an ammeter in series with the component and put a voltmeter around the component, then multiply the readings of voltage and current = power
Now draw a graph of the time in seconds on the x-axis against the temperature in degrees Celsius on the y axis
Then find the specific heat capacity using the equation SHC = power/mass x time/temperature change
Finally, repeat the practical using the copper and gold block to see how their SHCs compare. |
| How can thermal heat being lost through the roof be reduced? | A lot of thermal energy can escape from the roof of a house, this can be reduced with loft insulation, which has a low thermal conductivity, reducing the rate at which thermal energy passes through |
| How can the time and temperature change be calculated from the graph? | From the graph, the time and temperature change can be calculated by drawing a 90-degree triangle to measure both values |
| Why may the SCH of a practical be higher than aluminium’s SCH? | The SCH of a practical may be higher than aluminium’s SCH because the aluminium block is not insulated so energy is lost to the surroundings. This may be solved by insulating the block using foam on the sides and bottom. |
| What is the difference between a histogram and a bar chart? | A bar chart is used to display categorical data whereas a histogram displays numerical data therefore they are no spaces between the bars in histograms |
| how do you convert minutes into seconds and hours into seconds? | To convert minutes into seconds multiply the number of minutes by 60, and to convert hours into seconds multiply the number of hours by 3600 |
| Describe the specific heat capacity practical of oil | Begin by placing a beaker on a balance, now add the oil to the breaker and record its mass, place a thermometer and an immersion heater into the oil.
Read the starting temperature of the oil and warp the breaker in insulating foam to reduce thermal energy transfer to the surroundings.
Connect a joule meter and a power pack to the immersion heater and the joule meter states how many joules of electrical energy passes into the immersion heater.
Leave the set up for 30 minutes to allow the temperature to rise to a high enough level to ensure accurate thermometer readings.
Read the number of joules of energy that passed into the immersion heater and read the final temperature of the oil. |
| Why may the specific heat capacity practical using oil and a beaker be inaccurate? | The specific heat capacity practical may be inaccurate because thermal energy is passing out of the beaker into the air, this problem can be reduced by using an insulator with a lower thermal conductivity
Secondly, not all the thermal energy passes into the oil, this can be reduced by ensuring the immersion heated is fully submerged in the oil.
Thirdly there could be inaccurate readings of the thermometer, which can be avoided by using an electronic temperature probe
And lastly, thermal energy may not be spread evenly through the oil which can be reduced by stirring the oil |
| what are the advantages of fossil fuels? | Fossil fuels are reliable because they always provide energy when needed, they release a great deal of energy which can be useful in the case of aeroplanes that use jet fuel made from oil, in addition to this fossil fuels are abundant and relatively cheap, and they are extremely versatile: they can be used for heating, transportation and generating electricity |
| What are the disadvantages of fossil fuels? | Burning fossil fuels releases a huge amount of carbon dioxide, they are non-renewable which means they aren’t being replenished/replaced as we use them. Fossil fuels can also increase other pollutants such as burning diesel in cars and trucks that releases carbon particles and nitrogen oxide |
| What is a key fact about nucleic power? | Nuclear power is non-renewable, when the nuclear power plants run they releases carbon dioxide, they run on elements such as uranium and plutonium |
| What are the advantages of generating electricity by nuclear power? | Once the nuclear power is running isn’t doesn’t release carbon dioxide, it is extremely reliable and generates a lot of electricity when wanted. |
| What are the disadvantages of generating electricity with nuclear power? | Nuclear power plants contain highly dangerous radioactive materials and if there is an accident these materials could be released into the environment.
At the end of its life, a nuclear power plant has to be decommissioned or dismantled which can take up to many years and is extremely expensive.
During the life and after decommissioning of nuclear power plants, generate large amounts of highly dangerous radioactive waste which must be stood for thousands of years before it’s safe |
| What’s an example of the effect of radioactive materials in nuclear power plants? | An example of the radioactive materials in nuclear power plants was in Japan, 2010, when a tsunami flooded the power plant, resulting in the release of radioactive material; over 150,000 people who lived in close proximity has to be evacuated and the clean-up/removal lasted many years. |
| Describe how the use of energy resources in the UK is changing | During the 1970s scientists began to realise carbon dioxide emissions could be leading to climate change, however, politicians didn’t see this as a serious issue. And energy from fossil fuels was valued for the economical factor of its inexpensiveness, while switching to renewable to alternatives costed money and therefore jobs.
However, in 2005, the Kyoto protocol committed countries to reduce greenhouse gas emissions.
The UK has one of the best locations for wind power in the world, over the last decade, the UK has opened a large number of wind farms. Other remunerable energy sources such a solar power and biofuels are increasing in the UK.
The UK’s future looks upon renewables providing the bulk of our electricity while nuclear power produces the base-load and gas provides electricity during periods of peak demand. |
| Define Renewable energy | A Renewable energy resources is one that is being (or can be) replenished as it is used |
| Give seven different types of renewable energies | Renewable energy resources include wind power, solar power and hydroelectric power, tidal power, biofuels, geothermal and wave power. |
| What are the advantages of Renewable energy resources? | Renewable energy resources do not run out and once in place, renewable energy resources don’t add carbon dioxide to the atmosphere. |
| What are the disadvantages of renewable general energy resources? | Renewable energy resources such as wind power and solar power are not reliable, as they fully depend on the irregular non-fixed patterns of the weather, while hydroelectric power is reliable, however habitats are destroyed when dams are built and valleys are flooded. In addition to this hydroelectricity is only useful in countries which have lots of rivers. |
| What are the advantages and disadvantages of tidal power? | Tidal power is very reliable but currently the UK doesn’t generate any electricity from tidal power, but there are proposals to build a tidal barrage cross the severn estuary which some people argue could be harmful to wildlife. |
| What are the nine energy stores? | The nine energy stores are LSG Cenek, or Light, Sound, Gravitational potential energy, Chemical, Electrical, Nuclear, Elastic potential energy, and Kinetic |
| What are the advantages of wave power and geothermal power ? | Wave power is reliable and has potential in the UK because it has an extensive coastline.
While geothermal energy that uses heat from the earth to generate electricity and heat buildings, is reliable but not commonly used in the UK. |
| How are biofuels produced and what are its advantages? | Biofuels are produced from a plant material, these plants tuck in carbon dioxide and they don’t add extra carbon dioxide to the atmosphere, therefore they are carbon neutral. Biofuels are very useful as we can use them to power vehicles such as cars and busses |
| What’s the problem with biofuels? | The problem with biofuels is that they use land to grow crops for fuel which could increase decreases for supply and therefore increases the cost of food/crops |
