P1 - Energy - Revision - GCSE Flashcards
Energy
What is energy
Something needed for stuff to happen
Energy
What is a system?
An object or group of objects
Energy
What is energy measured in?
Joules
Energy
What is the law of the conservation of energy?
Energy is never created or destroyed, only shifted from one store to another
Energy
What are the 8 stores of energy?
Kinetic
Thermal
Nuclear
Vibrational
Gravitational potential
Electric and magnetic / electromagnetic
Chemical
Elastic
Energy
What is chemical energy
Energy released from chemical fuels
Energy
Where is nuclear energy found
In the nuclei of atoms
Energy
What is vibrational energy?
Light and sound energy
Energy
What is elastic potential energy
The potential for something to spring back to its original position
Energy
What is gravitational potential energy
The potential for something to fall / something that an object has if it is able to fall
Gravitational potential energy
What is the equation of gravitational potential energy?
Ep = mgh
Gravitational energy - mass x gravitational field strength x height
Gravitational potential energy
What is the gravitational field strength on earth to 1dp
9.8 N/Kg
Gravitational potential energy
What is mass measured in for this equation?
Kg
Gravitational potential energy
What is gravitational potential energy measured in
Joules (J)
Gravitational potential energy
What is height measured in for this equation?
m - metres
Gravitational potential energy
What is the definition of gravitational potential energy
Something that an object has if it is able to fall
Gravitational potential energy
How many joules is one MJ
1 million Joules (10 to the power 6)
Gravitational potential energy
What method should you show your working with when working with this equation?
3 step method
State equation
State values
Work out answer
Power
What is power?
Rate at which an appliance shifts energy
Power
What is power measured in?
Watts
Power
What are watts in terms of joules?
Joules per second
Power
What is the equation for power? (Derivable from definition)
P = E / t
Power = energy shifted / time
Power
What symbols do we use for power, energy and time in the equation for power
P = power
E - energy
t - time
Power
What other equation describes power?
Power = work done/time
Power
What is work done?
Energy shifted x time
W = E x t
Efficiency
What is efficiency?
How much energy is converted to a useful store compared to how much energy is taken in
Efficiency
What is useful energy?
Desired energy
Efficiency
What is the equation for efficiency?
Useful energy in/total energy in
Can be asked for asa percentage - if so then multiply by 100