Energy, work & power

Created by

Marcelle Daniels

Cards (17)

Define energy stores 
The different ways in which energy is stored in objects
What is energy measured in?
Joules (J)
Define a system 
An object or group of objects
Energy store examples 
Magnetic, electrostatic, kinetic, gravitational potential, elastic, chemical, nuclear, thermal
What energy store do objects have when they are stretched, squashed or bent?
Elastic potential
Energy transfers 
The pathways via which energy can move from one energy store to another
How can energy be transferred? 
Mechanical, electrical, heating and radiation
In a falling object, energy is transferred from its gravitational potential store to its kinetic store
Define kinetic energy 
The energy an object possesses due to its motion, determined by its mass and speed
What is the equation for calculating kinetic energy?
Ek= 1/2 mv^2
Kinetic energy= the half of mass x velocity^2
Define gravitational potential energy 
The energy possessed by an object due to its height in a gravitational field
What is the equation for calculating gravitational potential energy? 
ΔEP = mgΔh
Change in potential energy= mass x gravitational field strength x change in height
What does an energy flow diagram show? 
It represents energy stores and transfers within a system, showing both the stores and the transfers taking place
What is a Sankey diagram?
Graphical representations of energy transfers, characterised by splitting arrows that show the proportions of energy transfers taking place
The principle of conservation of energy states 
Energy cannot be created or destroyed, it can only be transferred from one store to another
What do the different parts of a Sankey diagram represent?
The left-hand side represents the energy transferred into the system, while the straight arrow pointing to the right represents the useful energy output. The curved arrow represented wasted energy.
State the equation for wasted energy 
wasted energy= total energy in - useful energy out