Unit 2 - Ch 7 - Energy Flashcards
Energy
the capacity to do work or from a biological perspective, cause change
What are the forms of energy?
- Chemical
- Electrical
- Mechanical
- Radiant
- Thermal
- Atomic
Chemical Emergy
contained within covalent bonds within molecules
= fuels, wood, food
Electrical energy
flow of electrons; requires a circuit (flow)
-challenge to store at a large scale
Mechanical energy
energy associated with position or motion = wind trubines
Radiant energy
light energy (visible part of the electromagnetic spectrum) = solar voltaic, solar thermal
Thermal energy
heat energy; infrared wavelengths = geothermal, heat pumps
Atomic energy
energy wihin atoms
= nuclear fission (split atoms) and nuclear fusion (fuse atoms = sun)
Types of energy:
Potential and kinetic
Potential energy
Energy stored; not currently causing change - changes into kinetic energy when released.
= food, wood, fuels, dam when closed.
Kinetic energy
energy in action; causing change - some is used to make more potential energy
= metabolizing food, combusting wood / fuel, open dam
First law of thermodynamics
Energy cannot be created or destroyed - energy is conserved - law of conservation
Closed system
Total energy is constant
= the universe is believed to be a closed system
Second law of thermodynamics
energy transformations “lose” energy to a state of randomness
Entropy
measure of disorder or randomness - total entropy in a closed system always increases - predicts a heat death of the universe
