p1-p3 Energy P2 In Another Flashcards
What is a system
A system is an object or group of objects
What happens when a system changes
The way energy is stored also changes
How to calculate kinetic energy
1/2x mass x speed^2
How to calculate elastic potential energy
1/2 x spring constant x extension^2
How to calculate gravitational potential energy
Height x gravitational field strength x mass
What is the specific heat capacity
The energy required to raise the temperature of 1kg of a substance by 1°C or 1K.
How to calculate energy
Mass x specific heat capacity x temperature change
Define power
The rate at which energy is transferred or the rate at which work is done
Calculation for power
Energy transferred/time = work done/time
What is Conservation of energy
Energy cannot be created or lost but it is simply transferred or changed form
How to reduce energy wastw
Lubrication
• Oil in a motor
• Reduces friction
• So less energy is lost (as heat) through friction
Thermal Insulation
• Double Glazing
• Less useful thermal energy lost
What is efficiency
The efficiency is the ratio of the useful work done by a machine, engine, device, etc, to the energy supplied to it, often expressed as a percentage.
What happens when thermal conductivity is higher
The higher the thermal conductivity of a material, heat is allowed to travel through the material more easily, so the higher the rate of energy transfer by conduction across the material.
What is thermal conductivity in a building
Rate of cooling is low if walls are thick and thermal conductivity of the walls are low
• If the walls are thin metal sheets, heat would be lost very quickly.
Calculation for efficiency
Useful energy output/total energy input= useful energy output/total power input
How to increase the efficiency
Reducing waste output (lubrication, thermal insulation, etc.)
Recycling waste output (e.g. absorbing thermal waste and recycling as input energy)
Main energy uses
Transport
- Electricity generation
- Heating
Compare renewable energy resources to non renewable energy resources
Renewable energy is energy which can be replenished as it is used (e.g. wind will never stop).
- Non-renewable energy is used more for large-scale energy supplies due to the large energy output per kilogram of fuel - renewable resources cannot provide such a large amount of energy as easily.
Renewable energy has become more important due to the finite lifetime of fossil fuels, and so their development has become more important.
Renewable energy is not always the most reliable as:
• Solar doesn’t work in bad weather or night
• Wind is only intermittent.
Environmeral impact of fossil fuels
Involved in destroying landscapes,release harmful emissions such as co2 and methane
Environmental impacts of renewable energy resources
Release no emmisions,wind turbines can be considered an eyesore
Patterns and trends of energy use
During industrial revolution, fossil fuels became an important source of energy as it was easy to mine, and provided a lot of energy
- Only recently has renewable energy become more suitable - technology has had to develop a lot since industrial revolution to be able to harness such energy sources efficiently
- It is easier to use energy resources due to increasing pressure to cope with the public’s increasing power demands but harder to solve environmental issues due to political, social, ethical and economic considerations.
Define nuclear fuel
Elements that can be used to release massive amounts of
energy for generating electricity. Nuclear fuel is based on
uranium
What is a fossil fuel
A fuel, made from hydrocarbons, that formed millions of
years ago from the bodies of animals and plants. Fossil fuels
are a store of chemical potential energy.
What is geothermal energy
The energy resource found in Earth’s crust, due the thermal
energy of the rock of the crust is certain places on Earth.
What is bio fuel
Any type of fuel made from the bodies of organisms – such
as fuels made from plants
What are renewable energy resources
Describes energy resources that are, or can be, replenished (replaced) as they are used. E.g. biofuels, geotherma
What is a non renewable energy resource
Describes energy resources that cannot be replenished. In
other words, they get used up. E.g. fossil fuels, nuclear fuel.
What is electricity
A form of energy that we find extremely useful, since it can
be used to run so many devices. We use the energy
resources described here mainly (but not only) to generate
electricity.
What is hydroelectricity
Water stored behind a dam has gravitational potential
energy, so it is a store of energy we can make use of.
What is tidal energy
Tides in the sea come in and out twice a day. This is a massive movement of water, whose kinetic energy can be transferred usefully to electrical energy
What is wave energy
Waves in the ocean have kinetic energy. With the right
equipment, this energy can be transferred usefully to
electrical energy.
What is solar energy
The Sun is an abundant source of energy. Using solar panels,
we can transfer light energy directly into electrical energy.
We can also use the thermal energy from the Sun for
heating and for generating electricity
What is the national grid
Systems of cables and transformers
Explain why transferring the electricity directly to local homes is more efficient
than using the National Grid to distribute the electricity
Less energy is lost due to the cables being shorter
Describe the process of solar panels conducting light
Semi conductors conduct light rays and this creates a negatively charged electron which flows throughout the entire surface.Turns light rays into electrical energy
How does a Nuclear power plant station work?
- The nuclear reactor core contains fuel rods made of uranium or plutonium. 2. When neutrons hit the fuel rods, they split the atoms in a process called nuclear fission. This releases a tremendous amount of heat energy. 3. Water circulating around the fuel rods gets heated by this process. 4. The hot water is used to produce steam. 5. The steam spins a turbine, which is connected to a generator. 6. As the turbine spins, the generator produces electricity. 7. After spinning the turbine, the steam is cooled back into water and recirculated to be heated again, repeating the cycle.
How does a hydro electric power station work?
Water is in a resevouire and one day a gate is opened which allows water to pass through and move the turbines which generates electricity through a generator.It is then put through a transformer to increase the voltage and is then sent to homes.
How does wind work?
- The wind causes the turbine blades to rotate around a rotor. 2. The rotating blades spin a shaft inside the nacelle, which is connected to a gearbox. 3. The gearbox increases the rotational speed and transfers it to a generator.4. The generator converts the mechanical energy from the rotating shaft into electrical energy.5. The generated electricity is transmitted down the tower and sent through underground cables to a substation. 6. At the substation, the voltage is increased for efficient transmission over long distances to the electrical grid.
How does wave work?
A wave generator uses wave motion to drive a generator move up and down, this turns the generator to mechanical energy to electrical energy which is transferred to the shore via a cable
How does tidal work?
Water flows through turbines, generating electricity as tides come in and out.
It works through the natural rise and fall of ocean tides.
It utilizes the gravitational pull of the moon and sun, along with the rotation of the Earth
Which energy resources a renewable and not renewable
Renewable Non renewable
Geothermal Coal
Hydro electric. Oil
Tidal. Gas
Wave. Nuclear
Wind
Biofuel
Operation of a fossil fuel power station?
Starts of with coal being brought by normally truck.It is then put in a fire in the boiler room.Water is then passed through which is heated and once it reaches a certain temperature it starts to create steam.the water is then cooled and This steam then pushes a turbine which then generates electricity through a generator,it is then pushed through a transformer which increases the voltage.
Why biofuels are considered carbon nuetral?
This is due to when carbon is released it balances by the co2 absorbed from the atmosphere during the growth of the plant.
Problems with biofuels
We can see a problem with biofuels is that there isnt enough to source people for there daily needs.Its also quiet expensive
Benefits and negatives of renewable energy resources
Benefits:Cheap to maintain,re usable,energy resource is unlimited
Negatives:Expensive,un reliable
The purpose of pumped storage systems.
We can see the benefits and purpose of it is to save more energy for a later use.For example if less energy is used in the night instead of turning the energy resource off.Let it run at night but save it for the day when needed more.Another benefit is this reduces costs.
How does a solar cell work?
Absorption of Sunlight: Solar cells are made of materials, like silicon, that can absorb photons (particles of light) from the sun.
Generating Electricity: When sunlight hits the solar cell, the energy from the photons knocks electrons loose from the atoms in the material, creating an electric current.
Electricity Collection: The electric current generated flows through the material and is collected by metal contacts on the cell’s surface.
Direct Current (DC): Solar cells produce direct current (DC) electricity. This can be used to power devices directly or stored in batteries for later use.
How does geo thermal work?
They use drills to drill down and drill the earths hot core which heats water and then turns into steam which turns a turbine and generates electricity through a generator,the water is then cooled to be re used
How does acid rain and climate change affect our planet?
Harms Nature: Acid rain damages plants, trees, and water bodies.
Dirty Water: It makes rivers and lakes too acidic for fish and other animals.
Health Issues: Breathing it in can cause lung problems, and drinking acid rain water isn’t safe.
Eats Buildings: It wears away buildings, bridges, and statues.
Costs Money: Fixing the damage caused by acid rain costs a lot of money.
Climate Change:
Gets Hotter: The Earth is warming up because of pollution.
Crazy Weather: We get more floods, droughts, and storms.
Animals in Trouble: Animals and plants are losing their homes.
Makes People Sick: Breathing dirty air from climate change can hurt our health.
Costs a Ton: Dealing with climate change costs a lot of money, like fixing things after big storms.
evaluate methods of reducing
damage caused by waste products of
fossil fuels and nuclear fuels.
Fossil Fuels:
Carbon Capture and Storage (CCS): Traps carbon dioxide emissions from power plants and stores them underground.
Nuclear Fuels:
Nuclear Waste Recycling: Reprocesses spent nuclear fuel to recover usable materials and reduce waste volume.
How is the national grid designed to reduce energy loses during transmission
Higher voltage which reduces currents which reduces energy lost
List the energy stores
Kinetic, gravitational, elastic, electrostatic, chemical, thermal,nuclear,magnetic
When does kinetic energy act
In a moving object
When does chemical energy act
A fuel or battery
When does gravitational energy act
An object above the ground
When does elastic energy act
A stretched or squashed object
When does thermal energy act
Due to substances temp
When does magnetic energy act
2 seperated magnets
When does nuclear energy act
Radioactive decay
What is energy
The ability to do work
List the energy transfers
Waves,heating,electrical current,mechanical
Benefits and negatives of solar power
No pollution once installed
✅ Renewable and free to use
❌ Expensive to set up
❌ Doesn’t work at night
Benefits and negatives of wind power
✅ No greenhouse gases
✅ Land can still be used for farming
❌ Noisy and can spoil the view
❌ Not always windy
Benefits and negatives of hydroelectric power
✅ Reliable energy source
✅ Can store energy for later use
❌ Destroys habitats by flooding land
❌ Expensive to build dams
Benefits and negatives of geothermal power
✅ Reliable – works all the time
✅ Little environmental impact
❌ Only works in certain areas
❌ Expensive to drill deep underground
Benefits and negatives of bio fuel
✅ Uses waste materials
✅ Carbon-neutral (absorbs CO₂ before burning)
❌ Produces some CO₂ when burned
❌ Large areas of land needed for crops
Benefits and negatives of coal
✅ Cheap and reliable
✅ Lots available in some countries
❌ Produces a lot of CO₂ (global warming)
❌ Mining damages the environment
Benefits and negatives of crude oil
✅ High energy output
✅ Used in transport and industry
❌ Produces CO₂ and can cause oil spills
❌ Running out quickly
Benefits and negatives of natural gas
✅ Cleaner than coal and oil
✅ Reliable energy source
❌ Still releases CO₂
❌ Gas leaks are dangerous
Benefits and negatives of nuclear power
✅ No CO₂ emissions
✅ Produces a lot of energy
❌ Risk of nuclear accidents
❌ Radioactive waste is hard to dispose of
Benefits and negatives of tidal energy
✅ Reliable – tides happen twice a day, every day
✅ No greenhouse gases – environmentally friendly
❌ Expensive to build tidal barrages
❌ Harms marine life – changes habitats for fish and other sea creatures
Benefits and negatives of wave power
✅ Renewable – waves never stop
✅ No greenhouse gases – environmentally friendly
❌ Unreliable – depends on wave strength
❌ Expensive to build and maintain
Describe the process of a solar power tower
A solar power tower uses heliostats (mirrors) to reflect sunlight onto a receiver at the top of a tower. This heats a fluid, often molten salt, which stores thermal energy. The heat is used to produce steam, which drives a turbine connected to a generator to generate electricity. The system can store heat for use even when the sun isn’t shining.
Which power station has the fastest start up time
Gas-fired power stations/hydroelectric
Which power stations have the slowest start up time
Nuclear/coal
What is the base load
Base load is the minimum level of continuous electricity demand that a power grid requires over a period of time.
In theory biofuels should be carbon neutral, but in reality they are not.
In order to grow the biofuels, we often have to clear land by cutting down trees. This means the trees can no longer photosynthesise and absorb CO2 themselves, and will also release large amounts of Co2 if burned.
In addition, it usually requires a lot of energy to harvest, process, and transport the biofuels, which itself will produce a lot of CO2.
What is an open system
Can gain or lose energy to the outside world
What is a closed system
A system which cannot gain or lose energy to the outside world
Is mass always the same anywhere in the universe
Yes it is
A ball of mass 0.2 kg is thrown upwards with a speed of 2 m/s.
Calculate the maximum height reached by the ball. Example question
Kinetic=1/2xmxv^2
Kinetic energy=1/2x0.2x2^2=0.4J
Calculate maximum height reached:
maximum gravitational potential energy = initial kinetic energy
GPE = mass x gravitational field strength x height OR GPE = m x g x h
0.4 = 0.2 x 10 x h
H=0.4/0.2x10=0.2
By what factor does kinetic energy increase by
4
What do we measure energy in
Joules
Investigation into specific heat capacity
First, measure the mass of the block using a balance.
Place the block in a container, surrounded by insulating material (such as bubble wrap) to reduce heat losses from the block.
Place a thermometer into the container and then connect a power supply, heater and ammeter to the block. This is shown in the diagram below.
Record the starting temperature of the block using the thermometer.
Turn the power supply on and start a stopwatch at the same time.
Record the current
(I)
(I) from the ammeter and the potential difference
(V)
(V) from the power source.
After
10
minutes
10 minutes, measure the final temperature of the block using the thermometer.
What is dissipation
A term used when energy is wasted
What is rhe inrernal energy
The total kinetic and potential energy of the particles in an
object
Formula for calculation of power wasted
Power wasted=total power in-useful power out
How does the mechanical energy pathway work
when a
force acts and something
moves)
How does the electric energy transfer work
When a current flows
How does the heating energy transfer work
Energy is transferred from a hotter object to a colder one (e.g. conduction)
How does the radiation energy transfer work
A wave such as light,microwaves or sound
What is an isolated system
A system that does not allow the transfer of matter or energy to or from its surroundings
What is kinetic energy
The amount of energy an object has as a result of its mass and speed
If an object speeds up what happens to its kinetic store
Energy is transferred
If a object slowes down,what happens to its kinetic energy store
Energy is transferred away
What is the gravitational potential energy
Amount of energy an object has in its gravitational store.
If a substance has a low heat capacity what does this mean
It heats up and cools down quickly
Takes less energy to change temp
If a substance has a high heat capacity was does this mean
It heats up and cools down slower,requiring more energy
Change in objects gravitational potential energy store formula
Weight x the change in height
Change of the gravitational potential energy store
Mass x gravitational field strength x change of height
Another equation for power including watts
Power=watts/time
What does it mean if a system has a high efficiency
means most of the energy transferred is useful
What does it mean if a system has a low efficiency
means most of the energy transferred is wasted
