4 Energy resources and energy transfers Flashcards
Energy Stores
- Chemical
- Kinetic
- Gravitational potential
- Elastic
- Thermal
- Magnetic
- Electrostatic
- Nuclear
Energy Transfers
mechanically, electrically, by heating, by radiation (light and sound)
Principle of conservation of energy
Energy can’t be created or destroyed, only transferred
Efficiency Equation
Efficiency = (Useful Energy Output / Total Energy Output) * 100
Conduction
Transfer of heat in solids through the vibration of particles
Convection
- Transfer of heat in fluids (liquids and gasses) through a convection current.
- The upward movement of warmer, less dense areas of fluid.
Radiation
Transmission of heat by electromagnetic waves (IR).
Dull surfaces - good absorbers and emitters of heat
Shiny surfaces - poor absorbers and emitters of heat
Work done
- Work done(J) = Force(N) x Distance Moved (m)
- Work done = Energy transferred
Gravitational potential energy equation
Gravitational potential energy(J) = Mass(Kg) x Gravitational field strength(N/Kg) x Height(m)
Kinetic energy equation
Kinetic energy(J) = 1/2(Mass x Velocity²)
Power equation
Power(W) = Work done(J) / Time taken(s)
Types of energy
Nuclear, Chemical, Magnetic, Gravitational potential, Kinetic, Thermal, Elastic potential, Electrostatic
Nuclear energy
Pros:
+No fuel is burnt, no greenhouse gasses produced
+Cheap
Cons:
-Risk of accident
-Hard to disposal radioactive waste
Thermal —(Mechanical)—> Kinetic —(mechanical)—> Electrical
Solar Power, electrical
Pros:
+Renewable
+Clean
Cons:
-Expensive
-Land lost
-Unreliable
Nuclear —(Radiation)—> Electrical
Solar power, heat
Pros:
+Renewable
+Cheap
+Clean
Cons:
-Unreliable
Nuclear —(Radiation)—> Thermal —(Mechanically)—> Thermal
