Energy Flashcards
(24 cards)
what are the energy stores?
chemical energy
kinetic energy
gravitational potential energy
elastic potential energy
thermal energy
magnetic energy
electrostatic energy
nuclear energy
what is a chemical energy store and give an example?
an object or substance from which energy can be released by a chemical reaction
e.g. a battery
what is kinetic energy and give an example?
anything that is moving has this
e.g. a car
what is gravitational potential energy give an example?
anything in a gravitatipnal field (so anything that can fall)
e.g.a plane
what is elastic potential energy and give an example?
anything which has been stretched
e.g. a spring or elastic band
what is themal energy and give an example?
the higher the temperature the more of this energy
e.g. fire
what is magnetic energy and give an example?
magnets that are attracting or repelling
e.g. magnets
what is electrostatic energy and give an example?
two electric charges that attract or repel
e.g. lightning or a charged balloon sticking to a wall
what is nuclear energy and give an example?
the energy in the nucleus of the atom
e.g. the sun
what are the 4 transfer pathways?
-mechanical (force applied to move an object a certain distance)
-heating (temperature change so energy flows from a hotter to a colder area)
-electrical (charge flows through an electrical circuit)
-radiation (transfered by a wavesuch as light, infared or sound or particles)
what is the gravitational field strength on earth?
9.81 N/Kg
what is the law for conservation of energy?
energy can’t be created or destroyed
if it appears to of been created or destrpyed then the energy has either been dissipated or transfered
what is the general trend between kinetic and thermal energy?
the more kinetic energy the more thermal energy generally
what is energy efficiency?
the percentage of useful work performed by a machine or a process compared to the energy expended
how can energy efficiency combat climate change?
more energy efficient devices can be produced with less waste which means less CO2 polluting the air. This means the planet will not heat up as quick leading to less climate change.
how can you increase the rate of enervgy transfer?
one way is you can increase the thermal conductivity of a material to increase the rate of energy transfer
increasing the thermal conductivity of a wall increases the rate of cooling
what is thermal conductivity?
a measure of an objects ability to conduct heat
what factors affect thermal conductivity?
the temperature difference across the material (the greater temperature difference the more conduction)
the thickness of the material (the more thick the material the less conduction)
what is the experiment investigating the thermal conductivity?
Set up the apparatus by placing a small beaker inside the larger beaker
Fill the small beaker with boiling water from a kettle
Place a piece of cardboard over the beakers as a lid. It should have a hole suitable for a thermometer and place the thermometer through this hole and into the water in the small beaker
Record the temperature of the water in the small beaker and start the stopwatch
Record the temperature of the water every 2 minutes for 20 minutes, or until the water reaches room temperature
Repeat the experiment, each time changing the cardboard for another insulating material (in any order) and also without any insulation at all
what are some renewable energy sources?
-solar
-wind
-biomass
-geothermal
-wave
-tidal
-hydro-electric
what are some non renewable energy sources?
-coal
-oil
-gas
-nuclear
what is a renewable energy source?
a renewable energy source is a source of energy that is being or can be replenished as it is used
what is power?
the rate at which work is done
What are the units for power?
Watts
