P1. Conservation and dissipation of energy Flashcards
Systems in Physics
What are energy transfers measured in?
It is measured in units of Joules (J) (This is regardless of what type of energy is stored ie. kinetic or chemical)
what is a system
An object or group of objects
when describing the changes within a system, only the objects or group of objects and the surroundings need to be considered. what are the 3 systems and what is there meaning?
There are 3 systems.
An open system allows the exchange of energy and matter to or from its surroundings
A closed system can exchange energy but not matter to or from its surroundings
An isolated system does not allow the transfer of matter or energy to or from its surroundings
Energy Stores & Transfers.
Energy stores.
What are energy stores?
The total kinetic and potential energy of the particles in an object
Kinetic
The energy of a moving object.
Gravitational (joules (J))
Energy that an object has due to its position above the ground. it gains gravitational energy when the object is lifted and it looses it when dropped
Elastic
The energy stored when an object is stretched or squashed.
Electrostatic
The energy due to forces of attraction (or repulsion) between two charges
Chemical
Energy found in fuels, foods, or in batteries. This energy is transferred during a chemical reaction.
Nuclear
The contained within the nucleus of an atom.
Thermal
Energy a substance has due to its temperature
Magnetic
The energy stored when repelling poles have been pushed closer together or when attracting poles have been pulled further apart.
Energy transfers
what are energy transfers
Energy transfer is the process by which energy is relocated from one system to another, for example, through the transfer of heat, work or mass transfer.
mechanical
When a force acts on a body eg. a collision
Electrical
Electricity can transfer energy from a power source, such as a cell, delivering it to a components within a circuit.
