Flashcards in Energy Transformations Deck (24)
what is energy
Energy is the ability to do work. It is what makes matter move or change. Energy can be categorised in to two broad categories, kinetic and potential energy.
what is work
A measure of energy transfer when an object is moved over a distance by an external force. When a force acts upon an object causing displacement (change in position, shape or doing something physical).
three requirements for work
› There are 3 requirements for work to take place. Force, displacement and cause. A displacement must exist that has been caused by the force, in order for a force to qualify as completing work.
what is potential energy
Energy that is stored
Stored in the bonds of chemical compounds, like atoms and molecules. This energy is released when a chemical reaction takes place. Usually once chemical energy is released from a substance, that substance is transformed into a completely new substance.
Nuclear energy is stored in the nucleus of atoms. The energy is released through nuclear fission or nuclear fusion.
Energy that is stored in an object when there is a temporary strain on it. The energy is stored in the bonds between atoms. The bonds absorb energy as they are put under stress and release it when they relax (object returns to original shape).
gravitational potential energy
Gravitational energy is the energy stored in an object due to its height above the earth.
› Gravity is a force which tries to pull two objects towards each other. Earth’s gravity is what causes objects to fall.
Nuclei are split apart.
Nuclei are fused together.
list all potential energy
chemical, elastic, nuclear and gravitational potential energy
the energy of moving objects
list of kinetic energy
radiant/light, electrical, sound and thermal/heat
The energy of electromagnetic energy that travels in transverse waves (these waves can travel through space and do not require a medium). Electromagnetic radiation is made up of tiny particles called photons.
Energy caused by moving electric charges called electrons. The faster the charges move the more electrical energy they carry.
Sound is the movement of energy through a substance and is caused by vibrations. Sound is transmitted in longitudinal waves. It cannot travel through a vacuum as it requires medium, in a vacuum there are no atoms to transmit the vibrations.
Produces when a rise in temperature causes atoms to move faster and collide with each other. The hotter a substance is the more its particles move and the higher its thermal energy.
difference between heat and temperature
Heat is the total energy of molecular motion in a substance. Temperature is a measure of the average molecular motion in a substance.
The sum of kinetic and potential energy in an object that is used to do work, also can be explained as the energy of an object due to its motion, position or both.
› As an object moves faster more energy is stored.
law of conservation of energy
States that energy cannot be created or destroyed, just transformed from one state to another or transferred between objects.
what does the law imply
law implies that the amount of energy present on the earth is always the same.
The change of energy from one form to another. An example of this is a natural gas stove oven which converts chemical energy from burning into thermal energy used to cook food.