Energy Resources and Energy Transfers Flashcards
Suggest one energy store that energy is transferred to when energy is wasted by a crane?
Thermal
Suggest one way in which energy is wasted by a fan?
The heating of the fan
Where is energy transferred from when a skydiver is falling from an aeroplane?
Gravitational potential energy store
Where is energy transferred from when a substance is undergoing a nuclear reaction
Nuclear energy store
Where is energy transferred from when a stretched spring returns to its original shape
Elastic Potential Energy store
Where is energy transferred from when a piece of coal burns
Chemical Energy store
How is energy transferred from the mains to the kettle
Electrically
State the principle of conservation of energy
Energy can’t be created or destroyed only transferred
Efficiency equation
Efficiency = Useful output energy transfer/ Total input energy transfer
What is power
Power is the rate of doing work. The units are Watts.
Why is the efficiency of an appliance always less than 100%
Some energy is always dissipated, so less than 100% of the input energy transfer is transferred usefully.
What is the equation linking power, work done and time?
Power = work done / time
Name two ways in which flasks will transfer energy by heating to the gel surrounding them
Conduction + Radiation
Which of the following is not an example of convection?
the heating of a large room by a radiator
the heating of water in a kettle
the transfer of energy by heating through a copper pan
hot air rising up
C - the transfer of energy by heating through a copper pan
What is the definition of power
The rate of energy transfer
What is the equation that links work done, force applied and distance moved in the direction of the force?
W = F x d
When hot water is poured into a Leslie cube, what side would feel the warmest when you place your hand in front of the surface of it.
Matt Black
When hot water is poured into a Leslie cube, what side would feel the coolest when you place your hand in front of the surface of it.
Matt white
Name two methods of energy transfer
Mechanically (by a force doing work)
Electrically (work done by when a current flows)
Heating
Radiation
State the equation linking energy in an objects kinetic energy store with mass and speed.
Kinetic energy =
0.5 x mass x (speed)^2 / Ek = 0.5 x mv^2
When a ball is thrown upwards, how does the way energy is stored change?
- Transferred from the chemical stores of the arm and the ball (and the gravitational energy store of the ball)
- Once it’s released, energy is transferred from the kinetic energy store of the ball to its GPE store.
