Science - Energy Transfer and Sources Flashcards
What are the energy stores?
Kinetic - anything moving has energy in its kinetic energy store
Thermal-
Chemical- anything that can release energy by a chemical reaction
Gravitational potential- anything that is in a gravitational field / anything that can fall
Elastic potential- anything stretched
Electrostatic- 2 charges that attract or repel each other
Magnetic - 2 magnets that attract or repel each other
Nuclear - atomic nuclei release energy from this store in nuclear reactions
What are the different ways energy can be transferred? (HERM)
Mechanically- a force acting on an object I.e pushing stretching squashing
Electrically - a charge doing work e.g charges moving around a circuit
By heating- energy transferred from a hotter object to a colder object e.g heating a pan on a hog
By radiation - energy transferred waves e.g energy from the sun reaching earth by light
Explain the law of conservation?
Energy cannot be created nor destroyed however it can be wasted transferred and stored
Does the total energy of a closed system change.
No as no energy can go in or out of the closed system . However energy can be transferred and stored within the closed system example. A cold spoon sealed in a flask of hot soup is a closed system.
Energy is transferred from the thermal energy store of the soup to the thermal energy store of the spoon by heating .
But no energy leaves the system. The total energy stays the same
How is energy transferred when an object is moving ( a moving object has energy in its kinetic energy store)
When an object is moving it has energy in its kinetic energy stores
Energy is transferred to kinetic energy stores if it speeds up and away if it slows down.
How do you find out the energy in the kinetic energy store
Kinetic energy (J) = 1/2 x mass (kg) x (speed)x(speed) [m/s]x[m/s] or for short
KE =1/2 x m x (VxV)
The . . . Its mass and the . . . . It’s going the more energy it has in its kinetic energy store
The greater the mass and the faster it’s going the more energy it has in its kinetic energy store
What is the equation to find out the percentage of efficiency
Efficiency (%) = useful energy transferred by the device (j) / total energy supplied to device (j)
Then multiply by 100 to find the percentage
What is the equation for the total energy input?
Total energy input = useful energy output + wasted energy
What are all the non-renewable fuels?
Oil , crude oil, natural gas, nuclear
What are the disadvantages of non renewable fuels? (Must memorise 3 for full marks)
-Fossil fuels are slowly running out (non renewable )
-Fossil fuels cause environmental problems
-Nuclear waste is very dangerous and hard to rid of
What are bio fuels made from?
Biofuels are made from plant products and animal shit
Renewable energy sources examples
Bio fuels. Wind. Sun(solar). Hydro electricity. Tides. Biomass. Biogas
What is 1 disadvantage of bio fuels ?
Lots of place is needed to grow the needs for biofuels. Lots of forest area is usually cut down for biofuel areas
How does hydro electric power produce energy
Falling water is how hydroelectric power gathers energy in the form of electricity
