Unit 1- Energy Flashcards
Work done equation
Force x distance
Kinetic energy equation
Half x mass x velocity squared
Power equation
Energy /time
Conduction
Occurs in solids, vibrating particles transfer energy to neighbouring particles
Convection
In liquids and gases, where particles move away from hotter to cooler regions
Efficiency equation
Useful output energy/ total input energy
What is geothermal energy
Underground thermal stores
What is hydroelectric power
Power transfers energy from kinetic store if falling water
Whst are biofuels
Renewable energy resources created from plants or animals
Gravitational potential equation
Mass x height x gravitational field strength
What is specific heat capacity
Amount of energy needed to raise temperature of 1kg of a substance by 1 degrees
Equation linking power current and resistance
Power = current squared x resistance
Equation linking energy charge and potential difference
Energy = charge x potential difference
Equation linking current potential difference and power
Power = current x potential difference
Equation linking power, time and work done
Power = work done / time
As the cyclist rides along the road what energy store decreases
Chemical
How does cycling uphill affect maximum speed of cyclist
Maximum speed is lower
Maximum force on pedals is constant
But gpe will increase
What does more energy efficient mean
Higher proportion of total input power is usefully transferred
Name the energy stores
Thermal , gravitational energy, magnetic, elastic potential, kinetic, nuclear, chemical, electrostatic
How can energy stores be transferred
By heat, mechanically, electrically, light, sound
Movement of gases
-random directions
-random speeds
What is the tiny spheres model
Came about before the discovery of the electron
Solid to gas
Sublimation
Advantages of nuclear power
Extremely reliable, no carbon dioxide produced therefore doesn’t contribute to climate change
What is thermal conductivity
Higher thermal conductivity, the higher the rate of energy transfer by conduction across that material
How to reduce thermal energy transfer from house
Construct building using materials with low thermal conductivity
Build house with thick walls as this reduces thermal energy transfer
What is work done
Whenever energy is transferred from one store to another
What happens when car brakes
Moving with kinetic energy and then brake presses against wheel of the car which causes friction, the kinetic energy store transfers to thermal energy store, this temp of breaks slows down car and stops it
What is a zero error
measuring system gives a false reading when the true value of a measured quantity is zero
