Energy 1 Flashcards
What is the equation linking kinetic energy, mass and velocity?
Ek= 0.5mv2
What are the units of energy?
joules
What are the units of mass?
kilograms
What are the units of velocity?
metres per second
What is the equation linking gravitationa field strength, gravitational potential energy and height?
Ep=mgh
What are the units of gravitational field strength?
newtons per kilogram
What is the equation linking energy transferred, power and time?
P=E/t
What are the units of power?
Watts
What is the definition of power?
Power is the rate of transfer of energy or the rate of doing work
What is the equation linking power, time and work done?
P=W/t
What are the units of work done?
joules
What is the equation for calculating efficiency from energy?
Efficiency = useful energy output/total energy input
What is the equation for calculating efficiency from power?
Efficiency = useful power output/useful power input
What is the type of energy transferred when a force moves through a distance?
Mechanical transfer
Mechanical transfer is??
The energy transfer when a force moves through a distance
Electrical transfer is??
energy transferred when a charge moves?
What is the energy transferred when a charge moves?
electrical transfer
What is the energy transferred by electromagnetic radiation?
Radiation transfer
Radiation transfer is??
The energy transferred by electromagnetic radiation.
Heat transfer is??
Energy transferred when an object is heated.
When an object is heated the energy transferr is a??
heat transfer
List the 4 energy transfer pathways.
Mechanical, electrical, radiation and heat.
List 4 energy stores.
Four from: chemical, kinetic, gravitational potential, elastic potential, internal, nuclear, magnetic, electrostatic.
Energy stored in objects which move.
kinetic
What is a kinetic energy store
Energy stored in objects which move
Chemical energy is stored as??
chemicals waiting to react
A battery is a store of __________ energy.
chemical
Food is a store of __________ energy.
chemical
A moving object is a store of ____________ energy
kinetic
What is a gravitational potential store?
energy storred in objects raised up against the force of gravity.
A rock at the top of a hill is a store of ___________ energy.
gravitational potential
What is an elastic potential store?
Energy stored in an object which has been stretched or compressed.
A compressed spring is a store of ___________ energy
elastic potential
An inflated balloon is a store of __________ energy
elastic potential
The internal energy store is?
energy stored in the movement of particles.
The internal energy store of an object can be changed by??
heating or cooling
Energy stored in the nuclei of atoms is in the __________ store.
nuclear
What is a nuclear energy store?
Energy stored in the nuclei of atoms that can fuse or split.
What is the name of the process in which the nuclei of atoms fuse together?
fusion
What is the name of the process in which the nucleus of an atom splits?
fission
What is the magnetic energy store?
Energy stored in magnets that are attracting or repelling
What is the electrostatic energy store?
Energy stored n electric charges that are attracting or repelling
Name two non-renewable energy resources
Fossil fuels, nuclear fuel
What are some advantages of fossil fuels as an energy resource?
reliable, cheap
What is a reliable energy source
one which can produce energy all the time.
What are some disadvantages of fossil fuels?
carbon dioxide (greenhouse gas) produced leading to global warming. Can produce sulphur dioxide causing acid rain.
What are some advantages of nuclear fuel?
No carbon dioxide produced, reliable.
What are some disadvantages of nuclear fuel?
nuclear waste remains radioactive for thousands of years. Expensive to build and decommission
List 4 renewable energy resources.
Any 4 from: biofuel, wind, hydroelectricity, geothermal, tidal, wave, solar.
What are some advantages of biofuels?
carbon neutral, reliable
What are some disadvantages of biofuels?
production of fuel can damage ecosystems and reduce variety of crops grown
What are some advantages of wind power?
No carbon dioxide produced
What are some disadvantages of wind power?
unreliable, expensive to construct
What are some advantages of hydroelectricity?
No carbon dioxide produced
What are some disadvantages of hydroelectricty?
blocks rivers preventing fish migration, unreliable (may not produce electricity during droughts)
What are some advantages of geothermal energy?
doesn’t damage ecosystems, reliable.
What are some disadvantages of geothermal energy?
fluids drawn from ground may contain greenhouse gases such as CO2 and methane.These contribute to global warming
What are some advantages of tidal energy?
No carbon dioxide produced.
What are some disadvantages of tidal energy?
unreliable - tides vary, may damage tidal ecosystem
What are some advantages of wave power?
No carbon dioxide produced
What are some disadvantages of wave power?
unreliable - may not produce electricity when calm seas
What are some advantages of solar power?
No carbon dioxide produced
What are some disadvantages of solar power?
unreliable - no electricity produced at night and limited on cloudy days. Expensive to construct.
What term is used to describe energy becoming spread out or transferred to a “wasted” store?
dissipation
What term is used to describe a method for reducing unwanted energy transfers by reducing friction?
lubrication
What is a thermal insulator?
A non-conductive material which reduces thermal energy transfers.
What is the name for a method of reducing energy transfers by the use of non-conductive materials?
insulation
What is the law of conservation of energy?
Energy cannot be created and destroyed but only transferred from one store to another.
Define specific heat capacity
The energy needed to raise the temperature 1 kg of a material by 1?C
