Topic 1: Energy (definitions) Flashcards
closed system
a system that experienced no net change in the total energy when energy transfers occur with it
conservation of energy
The law that energy can be transferred, stored or dissipated but never created or destroyed
efficiency
The ratio of useful output energy transfer to total energy input
elastic potential energy
The store of energy that stretched or compressed objects experience. It is directly proportional to the stiffness constant and to the square of the extension or compression
fossil fuels
coal, oil and gas
gravitational potential energy
The store of energy that all raised matter has. It is directly proportional to the mass of the object, the distance that it is risen and the gravitational field strength at that point
joule (J)
the unit used for energy
kinetic energy
The store of energy that all moving matter has. It is directly proportional to the object’s mass and to the square of its velocity
power
The rate at which energy is transferred, or at which work is done.
renewable energy resource
an energy resource that can be replenished whilst
it is being used
specific heat capacity
The amount of energy required to raise the temperature of 1kg of a substance by 1°C.
spring constant
A measure of a spring’s stiffness. The greater the value, the greater the force required to stretch or compress the spring by a given distance.
system
a single, or group of objects
thermal conductivity
The higher this value is for a given material, the higher the
material’s rate of energy transfer via conduction will be.
waste energy
Energy that isn’t usefully used for the purpose of the system
