energy

Created by

beya anish

Cards (65)

Reducing energy waste 
Lubrication
Thermal insulation
Thermal conductivity 
The higher the thermal conductivity of a material, heat is allowed to travel through the material more easily, so the higher the rate of energy transfer by conduction across the material
Main Energy Sources 
Non-renewable: Fossil Fuels, Nuclear Fuel
Renewable: Biofuel, Wind, Hydro-electricity, Geothermal, Tidal, Solar, Water waves
Renewable energy 
Energy which can be replenished as it is used
Non-renewable energy 
Used more for large-scale energy supplies due to the large energy output per kilogram of fuel
Main Energy Uses 
Transport
Electricity generation
Heating
Environmental Impact 
Extraction of Energy: Fossil fuels destroy landscapes, Wind turbines can be considered an eyesore
Use of Energy Sources: Fossil fuels release harmful emissions, Solar and wind create electricity with no emissions
Only recently has renewable energy become more suitable - technology has had to develop a lot since industrial revolution to be able to harness such energy sources efficiently
A system 
An object or a group of objects
Kinetic energy
What is the energy associated with movement?
Elastic potential energy 
What type of energy is stored in stretched objects
Nuclear energy
What type of energy is found in the nuclei of atoms?
Gravitational Potential Energy 
What type of energy is found in objects raised off the ground?
Thermal energy 
What type of energy is stored as heat?
Chemical energy 
What type of energy is found in bonds between substances?
Kinetic energy = 0.5 x mass x speed^2 
What is the equation to work out the kinetic energy of a moving object?
Elastic potential energy = 0.5 x spring constant x extension^2 
What is the equation to work out the elastic potential stored in a spring?
Joules (J) 
What is the unit for energy?
G.P.E = mass x gravitational field strength x height 
What is the equation to work out gravitational potential energy of an object raised off the ground?
kg 
What is mass measured in?
m/s 
What is speed measured in?
N/m
What is spring constant (Ek) measured in?
m
What is extension measured in?
0.2m
If an object started at 5cm long and stretched to 25cm then what would be the value for extension?
N/kg 
What is gravitational field strength measured in?
Change in thermal energy = mass x specific heat capacity x temperature change 
How can you calculate the change in thermal energy?
The amount of energy required to increase the temperature of 1kg of a substance by 1 degree celsius 
What is specific heat capacity?
Power
The rate at which energy is transferred or the rate at which work is done
Power = Energy transferred / time
How do you calculate power using energy transferred?
Power = work done / time 
How do you calculate power using work done?
Watts (W) 
What is power measured in?
1J 
How much energy is transferred each second if the power is 1W?
The higher the power, the faster the object would be lifted.
If you have two motors lifting a weight to the same height but one has more power, then what will be the difference between the rate at which they are lifted?
Energy can be transferred usefully, stored or dissipated, but cannot be created or destroyed
What is the law of the conservation of energy?
Wasted energy
What do we call energy that is dissipated?
There will be no net change in the total energy
In a closed system what will happen to the total energy?
Use lubricants or insulation to reduce energy being wasted as heat
How can we reduce the amount of waste energy in a system?
The higher the conductivity, the faster the rate of conduction
How does thermal conductivity of a material affect the rate of conduction across the material?
The thicker the wall, and the lower its conductivity, the slower it will lose heat. 
How does the thickness of a wall affect the rate of cooling of a building?
Efficiency = Useful output energy transfer/total input energy transfer 
How do you calculate efficiency using energy output?