energy Flashcards
What is the law of conservation of energy?
The amount of energy is neither created or destroyed.
What is the equation linking efficiency, useful output energy transfer and total input energy transfer?
Efficiency = useful power = total power
When energy is transferred in a closed system, what happens to the total amount of energy.
It stays the same.
what is the equation linking kinetic energy, mass and speed.
ke = 0.5 x mk x v2
the power out put of a hairdryer is 200w how much energy is transferred per second
2000 joules.
What are the seven stores of energy?
Kinetic, thermal, elastic potential, gravitational potential, chemical, electrostatic energy and magnetic.
Campbell met grace kelly to eat enchiladads.
How do we measure energy transferred?
Energy transferred = distance time x force
What is the measurement used for energy transferred?
Joules (j)
define gravitational potential energy?
Anything in a gravitational field (anything that can fall) it has energy in it potential.
How do you describe chemical energy?
energy with energy that can be released with chemical Reactions e.g. food, fuel, batteries,
How do you describe electrostatic energy?
When two electrostatic charges attract or repel each other.
How do you describe thermal energy?
Everything has some thermal energy so the hotter something is or the higher the temperature the more thermal energy it has.
What are the five main ways you can transfer energy between stores?
Heating, light and sound, mechanically, electrically.
What is conduction?
Conduction is when energy transfers through something being heated which causes particles to vibrate more. The heat energy transfers into kinetic energy. When the hot particle bump into the cold particles the cold particles get hotter. The hotter particles vibrate faster because they have more kinetic energy.
What is radiation?
In radiation the energy transfers through the air compared to conduction where it has to pass through solid objects. All objects radiate invisible waves and hotter objects radiate more then cooler one and more than they absorb so they cool down and the cooler objects absorb more so the heat up.
