Energy Flashcards
What is the control variable?
The one you keep the same
What is the independent variable?
The one you change
What is the dependant variable?
The one you measure
What is the independent variable in investigating specific heat capacity?
Changing the material
What is the dependent variable in investigating specific heat capacity?
Measuring specific heat capacity
What is the control variable in measuring specific heat capacity?
Initial temperature, insulating layer, time taken all kept the same
What is the units of mass in gravitational field strength?
Kg
What happens when an object falls?
It loses gravitational potential energy and gains kinetic energy.
What will stretching an object do?
Give it elastic potential energy
What does heating a material do?
Transfers the energy to its thermal energy store - temperature increases.
Explain what happens to a kettle when it is heated.
Energy is transferred to the thermal energy store of the
kettle. Energy is then transferred by heating to the water’s thermal energy
store. The temperature of the water will then increase.
What is specific heat capacity?
The amount of energy needed to raise the temperature of 1kg of a material by 1 celcius.
What are the eight energy stores?
Kinetic, thermal, chemical, elastic potential, gravitational potential, electrostatic, magnetic and nuclear.
What do all moving objects have?
Kinetic energy
What do all objects also have? (Aside kinetic energy)
Thermal energy
What is a chemical energy store?
Anything that can release energy during a chemical reaction.
What does the nucleus of an atom release?
Energy
Which 3 ways can energy be transferred?
Mechanically, electrically and heated
How can energy be transferred mechanically?
When work is done
How can energy be transferred electrically?
When moving charge does work
How can energy be transferred through heating?
When energy is transferred from a hotter object to a colder object.
State the conservation of energy.
Energy can never be created or destroyed, just transferred from one form to another.
What happens to energy in the conservation of energy?
Some energy is transferred usefully and some energy gets transferred into the environment. This is mostly wasted energy.
What is power?
The rate of transfer of energy - the amount of work done in a given time.
What is the equation for power?
Power = Energy transferred/time
or
Power = Work done/time
What does lubrication do?
Reduces the amount of friction.
Describe further what lubrication does.
When an object moves, there
are frictional forces acting. Some energy is lost into the environment. Lubricants, such as oil, can be used to reduce the friction between the surfaces.
What is conduction?
When a solid is heated, the particles vibrate and collide
more, and the energy is transferred.
What is convection?
When a liquid or a gas is heated, the particles move faster. This means the liquid or gas becomes less dense. The denser region will rise above the cooler region.
What doe insulation do?
Insulation reduces the amount of heat lost.
What are examples of insulators?
Thick walls, thermal insulation such as double glazing, loft insulation and cavity walls.`
What are examples of non-renewable materials?
Coal, oil, gas.
What are non-renewable materials?
Materials that will all run out, damage the environment but provide most of the energy.
What are renewable materials?
Materials that will never run out, not harmful to the environment but can be unreliable and not provide as much energy.
Describe efficiency.
When energy is transferred, some energy is wasted. The less energy that is wasted during the transfer, the more efficient the transfer.
