1 - Energy Flashcards
What is a closed system?
A closed system experiences no net change in total energy during energy transfers
What is the law of Conservation of Energy?
Energy cannot be created or destroyed. It can only be transferred from one Energy store to another.
What is the definition of efficiency?
The ratio of useful output energy to total energy output.
What is Elastic Potential Energy?
The energy store of a compressed or stretched object.
What is Gravitatonal Potential Energy?
The energy stored when an object is raised above the ground.
What is Kinetic Energy?
The energy an object has when it is moving.
What a Renewable Resource?
A source of energy that replenishes itself as it is used, e.i. it doesn’t run out.
What is a Non-Renewable Resource?
A resource that does not replenish as it is used, i.e. it will run out one day.
What is the unit of measurement for energy?
A Joule.
What is Specific Heat Capacity?
The amount of energy needed to raise 1kg of a substances temperature by 1°C.
What is Power?
The rate of an energy transfer.
What is a Spring Constant?
A measure of a springs stiffness.
What is Thermal Conductivity?
The rate of energy transferred through conduction.
What is a System?
A group of objects or a single object.
What is Work Done?
The energy transferred when a force is acted upon on object.
What is the equation for Kinetic Energy?
1/2 x mass (kg) x velocity² (m/s²)
What is the equation for Elastic Potential Energy?
1/2 x spring constant (N/m) x extension² (m)
What is the equation for Gravitational Potential Energy?
mass (kg) x gravitational field strength (N/kg) x height (m)
What is the equation for Specific Heat Capacity?
(mass (kg) x change in temperature (°C)) / change in thermal energy (J)
What is the equation for Power?
energy transferred (J) / time (s)
OR
work done (J) / time (s)
What is the equation for Efficiency?
(useful output energy / total energy output) × 100
How can efficiency be increased?
Lubrication or insulation, recycling waste energy.
What are the main non-renewable energy sources?
Coal, Oil, Gas, and Nuclear
What are the Renewable Energy Resources?
Biofuel, Wind, Solar, Tidal, Hydroelectric, Geothermal, and Water Waves.
What are the environmental impacts of energy extraction?
Landscape destruction, Visual pollution
What are the environmental impacts of using energy?
Fossil fuels release harmful emissions, whereas solar and wind release no emissions
