Energy Flashcards
What is a closed system
A system that experiences no net change in its total energy when energy transfers occur within it.
What is the conservation of energy
The law that energy can be transferred, stored or dissipated but never created or destroyed.
What is efficiency
The ratio of useful output energy transfer to total energy input.
What is 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.
Name types of fossil fuels
Oil, Gas and coal
What is 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.
What is a joule
The unit used for energy. Equal to the work done when a force of one Newton acts over a distance of one metre.
What is 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.
Define power
The rate at which energy is transferred, or at which work is done.
What is a renewable energy resource
An energy resource that can be replenished whilst
it is being used.
What is specific heat capacity
The amount of energy required to raise the temperature of 1kg of a substance by 1°C.
What is the 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.
What is a system
A single, or group, of objects
Define thermal conductivity
The higher this value is for a given material, the higher the materials rate of energy transfer will be via conduction
Define waste energy
Energy that isn’t usefully used for the purpose of the system
