P1- Energy Flashcards
What are the 11 stores of energy
Kinetic, Gravitational potential, thermal, chemical potential, light, sound, electrical, nuclear, elastic potential, electrostatic, magnetic
What is energy transfer
The same as work done, when energy is transferred, one energy store will get smaller and another larger
Description of kinetic energy
Energy an object has because it is moving/ the energy store associated with moving objects
Description of gravitational potential energy
The energy an object acquires when it changes height
Description of thermal energy
The energy a substance has due to its kinetic energy (movement of its particles, always transferred from hot to cold objects)
Description of chemical potential energy
A type of stored energy released by chemical reactions
Description of light energy
Transverse wave, form of electromagnetic radiation, contains protons
Description of sound energy
Longitudinal wave, transmitted by vibrations of the particles in the medium through which it is travelling
Description of electrical energy
Caused by moving electrical charges, carried by wires, the energy that electrons have as they flow around a circuit
Description of nuclear energy
Energy stored nucleas of an atom that holds the nucleas together
What can energy not be
Created or destroyed
Description of elastic potential
The store of energy that stretched or compressed objects experience
What can energy be
Stored, transferred or dissipated
What is joules
The amount of energy an object has
What does dissipated mean
The energy has been spread our to the point it is no longer useable
What is a system
An object or group of objects that interact.
When a system changes, what happens to the way energy is stored
The way energy is stored also changes
What is a closed system
Where no matter or energy can enter or leave
What are the 3 things the amount of energy transfers depends on
1) Temperature difference between the two objects (greater difference = greater rate of energy transfer)
2) The thermal conductivity of a material (higher = more energy transferred),
3) The thickness of the insulating material (thicker = less energy transferred)
What is useful energy transfer
When energy is transferred to the energy store a device is intended for
What is the energy store/ transfer of a javelin thrower
Chemical energy of athlete will decrease. Kinetic energy of javelin will increase and gravitational potential energy of javelin will also increase
What will energy always be wasted as
Heat and sound
What is efficiency
A measure of how good a device is at changing energy from one store to another
If a device is more efficient, will less or more energy be wasted
Less energy wasted
Efficiency equation
Useful energy output / total energy input
How are energy efficient light bulbs more efficient than normal light bulbs
They waste less energy, more of electrical energy that they are supplied with us converted into light energy and not heat
How is efficiency shown
As a percentage or decimal between 0 and 1
3 ways to improve the efficiency of energy transfers
1) Insulating objects
2) Lubricating objects
3) Making objects more streamlined
Work done equation
Work Done= Force x Distance travelled (in direction of force)
What does the gravitational potential energy at the top equal
The kinetic energy of the object just before it hits the ground
Equation for kinetic energy (Ek)
0.5 x mass x velocity^2
Gravitational potential energy (Ep) definition
The energy of an object with mass in a gravitational field suspended at a height above ground level
Equation for Gravitational Potential energy (Ep)
Mass x gravitational field strength x height
Gravitational field strength on earth
9.8 or 10 N/Kg
What is elastic potential energy
A force acting on an object may cause the shape of an object to change. Elastic objects can store elastic potential energy if they’re stretched
Equation for Elastic potential energy (Ee)
0.5 x spring constant (k) x extension^2
What is spring/stiffness constant
A measure of how many Newtons (N) of force are required to extend a material by 1m.
How is extension calculated
Extended length - Original length
Specific heat capacity definition
The amount of energy required to raise 1kg of the material by 1 degree Celsius
Equation for specific heat capacity
Energy= Mass x specific heat capacity (c) x temp change
Power definition
The rate at which work is done.
Power definition
Work done / time
Weight definition
The force due to gravity (gravitational field strength)
Weight equation
Mass x gravitational field strength
Renewable energy sources are…
Replenished at the same rate they are used
Non- renewable energy sources are..
Where the resource gets used up faster than it is reproduced
Renewable energy sources examples
Solar, Wind, Nuclear, Tidal/Wave, Biomass, Geo-thermal, Hydro-electric, fossil fuels
Solar energy
Sun light energy to electric. Generated by solar cells (panels)
Solar energy Advantages
Low running costs, no damage to environment
Solar energy disadvantages
Produces pollutants, high upfront costs, dependant on weather
Wind energy
Kinetic to electric energy, wind turns turbines to generate electricity
Wind energy advantages
Low running costs, no damage to environment
Wind energy disadvantages
Produces pollutants, high upfront costs, dependant on weather
Nuclear energy
Energy released from the nucleas during nuclear fission
Nuclear energy advantages
Produces large amounts of energy, doesn’t emit greenhouse gases, reliable
Nuclear energy disadvantages
Risk of nuclear disaster, expensive to build, have to store it safely for a long time
Tidal/ Wave energy
Dams that make use of tides difference in water level to generate electricity
Tidal/ Wave energy advantages
Large amount of electricity with no pollution, low running costs, doesn’t produce greenhouse gases
Tidal/Wave energy disadvantages
Dependant on weather, can cause flooding, takes up space
Biomass advantages
Cheap to make, easy to transport, carbon neutral
Biomass
Fuel made recently from living organisms, from plants or algae
Biomass disadvantages
Need somewhere to grow, produces greenhouse gases
Geothermal energy
Thermal energy generated and stored in earths crust. Directly for heat or to generate electricity
Geothermal energy advantages
Only damages environment slightly when installing, doesn’t produce pollutants, reliable over long time
Geothermal energy disadvantages
Expensive to build, only in certain areas
Hydroelectric energy
Dams that trap water coming from upstream, difference in water level generates electricity
Hydroelectric energy advantages
Large amounts of energy with no pollution, low running costs
Hydroelectric energy disadvantages
Only in certain locations, can cause floods
Fossil fuels energy
Formed form plants and sealife being put under extreme pressure and heat
Fossil fuels energy advantages
Reliable, large amounts of energy produced
Fossil fuels energy disadvantages
Greenhouse gases, finite resource
What are the three main fossil fuels
Coal, Oil and Gas
3 key points about fossil fuels
1) They will run out one day
2) They all do damage to the environment
3) They are reliable
What two things are energy resources used for
Transport and heating
