Energy Flashcards
What is a system?
an object or group of objects.
What is specific heat capacity?
the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.
What is power?
the rate at which energy is transferred or the rate at which work is done.
What is the relation between energy transfer and power?
An energy transfer of 1 joule per second is equal to a power of 1 watt.
What is the unit of power?
Watts.
How do you reduce unwanted energy transfers?
Through lubrication and the use of thermal insulation.
How does thermal conductivity effect energy transfer?
The higher the thermal conductivity of a material the higher the rate of energy transfer by conduction across the material
How is the rate of cooling of a building affected its walls?
The thickness of the wall does not affect thermal conductivity, if thermal conductivity is lower, heat transfer is lower so cooling would be slower.
What are the main energy resources available for use on earth?
fossil fuels (coal, oil and gas), nuclear fuel, bio-fuel, wind, hydroelectricity, geothermal, the tides, the Sun and water waves.
What is a renewable energy source?
An energy source being replenished as it is used that will never run out.
What is a non renewable energy source?
An energy source being used up at a faster rate than it can be replenished and will eventually run out.
What are examples of renewable energy sources?
Wind, waves, tides,hydroelectric, solar, geothermal, food, biofuels.
What are examples of non-renewable energy sources?
coal, oil, natural gas, nuclear fuels
What is one benefit to renewal energy sources?
They damage the environment less than non-renewable.
What is one drawback to renewal energy sources?
They don’t provide enough energy and often depend on weather-unreliable.
