Energy Flashcards
What is the law of conservation of energy?
Energy cannot be created or destroyed, only transferred, stored or dissipated.
Name 4 types of energy store.
Thermal, kinetic, chemical, gravitational potential
What is meant by an energy store?
It is where energy is kept in an object or system.
What is an energy transfer?
The movement of energy from one store or object to another.
Give an example of energy being transferred mechanically.
Lifting a weight or pushing an object.
What does it mean when energy is dissipated?
It is spread out or lost to the surroundings, often as heat.
What is thermal energy?
Energy stored in a substance due to its temperature.
What is kinetic energy?
The energy an object has due to its movement.
What is chemical energy?
Energy stored in the bonds of chemical substances, released during chemical reactions.
What is gravitational potential energy?
Energy stored in an object due to its position above the ground.
What is elastic potential energy?
Energy stored in a stretched or compressed object.
What is the unit of energy?
Joules (J)
What is efficiency?
A measure of how much input energy is usefully transferred.
What does a high efficiency mean?
Most of the energy is usefully transferred with little wasted.
What is the main form of wasted energy in most transfers?
Thermal energy
How can wasted energy be reduced?
By improving insulation or lubrication.
Name 3 renewable energy resources.
Solar, wind, hydroelectric
Name 3 non-renewable energy resources.
Coal, oil, natural gas
What is a renewable energy resource?
A source of energy that can be replaced and won’t run out.
Why do we need to reduce our use of fossil fuels?
They cause pollution and will eventually run out.
Name 4 ways energy can be transferred
Work done,mechanically,heating,radiation
