P1 - Energy Stores and Transfers

Created by

Luke Barnett

Cards (16)

Energy stores
kinetic
gravitational potential
elastic potential
thermal
chemical
nuclear
magnetic
electrostatic
Ways energy can be transferred
heating
waves
electric current
mechanically by forces
System
An object or group of objects
Closed system
A system where no energy can be transferred to or from the surroundings - the total energy in the system stays the same
Work done
Energy transferred when a force moves an object
Unit for energy
Joule (J)
One joule of work
The work done when a force of 1 N causes an object to move 1 m in the direction of the force
Energy transfer when a moving car slows down
Energy is transferred mechanically from the kinetic store of the car to the thermal store of its brakes - some energy is dissipated to the thermal store of the surroundings
Energy transfer when an electric kettle is used to heat water
The electric current in a kettle transfers energy to the heating element's thermal store - energy is then transferred by heating from the heating elements thermal store to the thermal store of the water
Energy transfer when a ball is fired using an elastic band
Energy is transferred mechanically from the elastic store of the elastic band to the kinetic store of the band - some energy is dissipated to the thermal store of the surroundings
Energy transfer when a falling apple hits the ground
Energy is transferred from the kinetic store of the apple and dissipated to the thermal store of the surroundings by sound waves
Unit representing one joule transferred per second
Watt (W)
Thermal conductivity
How well a material conducts heat
Materials with low thermal conductivity
Thermal insulators
Factors determining rate of thermal energy transfer through a material
Thermal conductivity of material
Temperature difference
Thickness of material
Factors affecting rate of heat loss from a building
Thickness of walls and roof
Thermal conductivity of walls and roof
Temperature difference between the two sides of wall/roof