Energy Study Guide

-quantity that flowed from a hotter object to a cooler one, warming it up.
-cause for warming, and change of phase

(Enabled particles of a substance to move farther apart until the attraction of the particles for each other became too weak to hold them together)

modern word for caloric?

the two kinds of change
1. When force is applied to objects that lift them or change their speed

2. When the temperature of an object is changed

What two ideas about energy were lost when the caloric idea was abandoned?
the storage and transfer of energy

the three principles guiding our modern view of energy
1. Energy can be viewed like substance-like quantity in a physical system

2. Energy can be cause change by flowing or transferring from one system to another

3. Energy stays the same (maintains identity) after being transferred

the ways information is like energy
-Information can be stored in books, on computer hard drives, CD-ROMS, etc.
-It can be transferred from place to place, but can’t touch it or measure its mass.
-Energy transformation also sometimes seems like the energy is changing rather than the physical system that gains or loses it. (even though info is moved from place to place, nothing about the info changes)

Describe the ways money accounts are like energy
Money is stored in accounts at the bank. There are checking accounts, savings accounts, etc. There is nothing different about money in any of these accounts. The money can be transferred back and forth from these accounts without changing the nature or quantity of the money.

State the names of the three “storage” accounts
thermal energy (Eth)
phase energy (Eph)
chemical energy (Ech)

thermal energy (Eth)
-energy stored by moving particles.
-The quantity of thermal energy stored by a collection of particles is related to their mass and velocity. (you would rather catch barehanded baseballs thrown by instructor than one by a major league pitcher) (it would hurt to be pelted by golf balls, but not by ping pong balls)

phase energy (Eph)
-energy stored in system due to arrangement of particles that exert attractions on one another. (energy account involved when phase changes occur)
-Attractions result in decrease of energy of a system of particles.
-As particles become more tightly bound, their phase energy is lowered.
-Solids possess lowest phase energy, and liquids possess more because the particles move freer. Gas possesses greatest amount because particles have completely broken free of each other.

chemical energy (Ech)
-the energy due to attractions of atoms within molecules.
-These attractions are chemical bonds because they are directed between specific atomsin the molecule.

three mechanisms to transfer energy

-the way energy is transferred between objects large enough to see that exerts force on another. (you can calculate work objects do on each other)

-the way that energy is transferred by collisions of countless microscopic objects.
-Energy is transferred from the hotter object to a colder one.
-If all the molecules have the same mass, then the hotter ones are moving faster than the colder ones.

-process which energy is transferred by absorption or emission of photons (particles of light).
-A light bulb filament can be heated to the point that it glows and this is the emission of photons that carry energy away from the filament.

Kinetic Molecular Theory (KMT)
1. Matter is made of tiny particles that are in constant random motion.
2. These particles exert long-range attractions and short-range repulsions on one another. Attractions bring about a reduction in the energy state (Eph ) of the system; repulsions bring about an increase in the energy.
3. A hotter sample is one whose molecules are moving (on average) faster than the molecules in a colder sample.