Test 2 Starts Friday Oct 18 Ends Monday Oct 21 Late day Tuesday Oct 22

16 Multiple Choice 4 Free Response Give yourself plenty of time!

Conduction

HOT COLD

WARM

Ordered

Disordered

Universal Heat Death

“This is the way the world ends, not with a bang but a whimper.”

T.S. Eliot

Gospel perspective

"every thing restored to its perfect frame"

Alma 11:44

Entropy and Comic Strips

Hot air balloon problem

Calorimetry – Ice in Water 50 grams of ice at -20 degrees C in

80 grams of water at 10 degrees C

You heat a disc with a hole in it. Will the hole expand or shrink,

or stay the same?

A. ExpandB. ShrinkC. Stay the same

Demo: Heat ring—does ball still fit?

In an ideal gas, if you double the volume of the container, while keeping the temperature and the number of molecules the same, the pressure in the gas

A. DecreasesB. Stays the

sameC. Increases

Suppose we have two jars of gas, one of helium and one of oxygen. If both jars have the same volume, and the two gases are at the same pressure and temperature, which jar contains the greatest number of molecules?A. Jar of helium

B. Jar of oxygenC. Both jars contain

the same number.Consider both gases to obey the ideal gas law. Also note that the mass of an oxygen atom is greater than the mass of a helium atom.

Cwater=4186 J/kg oC Cgold=129 J/kg oCWhich heats up faster using the same heat source?

A. 1 kg waterB. 1 kg goldC. They both heat up at

the same rate.

TmcQ Q is energy transferred

Hard WorkToday, many have forgotten the value of work. Some falsely believe that the highest goal in life is to achieve a condition in which one no longer needs to work. President David O. McKay (1873-1970) was fond of saying, "Let us realize that the privilege to work is a gift, that power to work is a blessing, that love of work is success."

Work is not a matter of economic need alone; it is a spiritual necessity.

-- BISHOP H. DAVID BURTON

The path shown below is adiabatic (Q = 0). The change in internal energy of the gas is

1. Positive2. Negative3. zero

P

V

In the path shown below, the gas returns to its original state. The net change in internal energy is

P

V

1. Positive2. negative3. zero

Start with 3 moles of an ideal monatomic gas at 20o and 1 atm. Compress to half of it’s volume isothermally. What the heat that enters, the work done on the gas, the change in internal energy, and the change in entropy?

Start with 3 moles of an ideal monatomic gas at 20o and 1 atm. Compress to half of it’s volume adiabatically. What the heat that enters, the work done on the gas, the change in internal energy, and the change in entropy?

Start with 3 moles of an ideal monatomic gas at 20o and 1 atm. I double the pressure isovolumetrically. What the heat that enters, the work done on the gas, the change in internal energy, and the change in entropy?

In the path shown below, the gas returns to its original state. The heat put into the gas is

P

V

A. PositiveB. negativeC. zero

One of the P-V curves below is for an isothermal process. The other

is for an adiabatic process. Which is adiabatic?

P

V

A

B

Two gases in separate containers have equal volumes, equal numbers of molecules, and the same internal

energy Eint. However, one gas is monatomic and the other is

diatomic. The pressure of the diatomic gas is

A. Less than that of the monatomic gas.

B. The same of that of the monatomic gas.

C. Greater than that of the monatomic gas.

The second law of thermodynamics says for a heat engine1. You can’t get more work energy out than

you consume in heat2. You can’t get out all of the heat energy as

work3. You will get out more work energy than

you consume in heat