Energy Flashcards
What is the law of conservation of energy
Energy cannot be created or destroyed, only transferred into different types
Rubbing a finger on a bench
Kinetic -> thermal and sound
Closing a switch (light bulb)
Chemical potential -> light and thermal
Roller coaster at top of hill
Gravitational potential -> thermal, kinetic, sound
Microwave oven
Electrical potential-> light, thermal, sound
Spring being stretched
Kinetic potential -> thermal, elastic
Nuclear fusion
Nuclear potential -> light, kinetic, thermal
What is efficiency
It is determined by the useful energy output and total energy output. The higher the efficiency, the less energy is wasted
What is infrared radiation
It is a type of heat transfer. It is the only type which does not require particles. The waves have a longer wavelength than visible light. All objects emit and absorb infrared radiation
What happens when an object is warmer or colder than its surroundings
If it is warmer, it emits more infrared radiation than it absorbs. If it is cooler, it absorbs more infrared radiation than it emits
What is thermal equilibrium
It occurs when an object reaches and remains at a constant temperature with another object it its surroundings. Amount of thermal energy absorbed is exactly equal to amount emitted. There is no change in energy
What happens on a sunny day with a black car and white car
Black car will become hotter faster as it will absorb the infrared radiation faster. Will absorb more than is emitted
What happens on a cold day with a black and white car
The black car will become colder quicker as it emits more infrared radiation than the white car and hence loses energy faster
Something is falling and accelerating
GP -> kinetic thermal sound
Something falling reaches terminal velocity and falls at a constant speed
GP -> thermal and sound
