Chapter+11,12+Thermodynamics

Chapter 11,12 Thermodynamics by Jakob Gordon

Ch11 Heat- the transfer of energy between a system and its environment due to a temperature difference between them.

Internal energy- U is the energy associated with the atoms and molecules of the system. It also includes kinetic and potential energy.

Calorie- the amount of energy necessary to raise the temperature of one gram of water by one degree.

Calorimeter- vessels that are good insulators

Calorimetry- analysis using calorimeters

Phase change- Change in a substance from one phase to another (solid, liquid, gas).

Latent heat of fusion- change from a solid to liquid or liqud to solid.

Latent heat of vaporization- change from a liquid to a gas or a gas to a liquid.

Conduction- energy transfer process due to temperatue difference.

Radiation- the transfer of heat by thermal waves.

Formulas media type="youtube" key="tQcB9BLUoVI" height="315" width="420" Ch. 12

First law of thermodynamics- there is no way to get a greater amount of energy out of a cyclic process than we put in Second law of thermodynamics- you always get less energy out than you put in

Formulas

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Problems

A student eats a breakfast containing a total of 3.20e2. He wishes to do the equivalent amount of work in the gym by performing curls with a 25kg barbell. How many times must he raise the weight to expent that much energy? He raises the weight .4m each rep.

A steel strut is 2.00m long with a mass of 1.57kg and a cross-sectional area of 1.00e-4 m^2. The strut absorbs a net thermal energy of 2.50e5J. Find the change in temp of the strut. Find the increase in length of the strut. If the strut is not allowed to expand because it's bolted at each end, find the compressional stress developed in the strut.



A 125g block of a unknown substance with a temp of 90.0 o C is placed in a Styrofoam cup containing 0.326 kg of water at 20.0 o C. The system reaches an equilibrium temp of 22.4 o C. What is the specific heat, of the unknown substance if the heat capacity of the cup is neglected.

Find the energy transferred in 1.00h by conduction through a concrete wall 2.0m high, 3.65m long, and .20m thick if one side of the wall is held at 20 o C and the other side is at 5 o C

The gas in the cylinder is at a pressure equal to 1.01e5Pa and the piston has an area of .100m^2. The piston is pushed up a distance of 4.00cm. Calculate the work done by the expanding gas on the surroundings.

A gas absorbs 5.00e3J of energy while doing 2e3J of work of the environment. Compute the change in the internal energy of the gas. If the internal energy now drops by 4.5e3J and 7.5e3J is expelled from the system, find the change in volume, assuming a constant pressure process at 1.01e5Pa.

A balloon contains 5 moles of a gas. As energy is added to the system by heat, the volume increases by 25% at a constant temp of 27 o C. Find the work Wenv done by the gas in expanding the balloon, the thermal energy Q transferred to the gas, and the work W done on the gas.



Questions Ch 11

1) Liquid helium has a very low boiling point, 4.2K, as well as latent heat of vaporization of 2.09e4 J/kg. If energy is transfered from the helium at the boiling point from an immersed electric heater at a rate of 10 W, how long does it take to boil away 2 kg of the liquid. a 69.7 min b 100 min c 40 min d 30 min

2) What is the unit for heat a calorie b joule c Celsius d Fahrenheit

3) How many calories are in 1 joule a 4.898 b 5.658 c 4.186 d 6.989

4) What is the first phase change of water a freezing b melting c boiling d condensing

5) How does convection transfer heat a by touch b by radiation c by air d by heat

ch 12

1) What is the area under the PV diagram a work b speed c acceleration d heat

2) What formula is equal to the work done on a gas a W=PV b W=-P∆V c W=P∆V d W=P

3) What does a heat engine do a takes in energy by heat and converts it to other forms b takes in energy by heat and partially converts it to other forms c takes in energy by heat and does nothing with it d thake in energy by heat and produces heat

4) Who came up with the second law of thermodynamics a Kelvin b Planck c Kelvin-Planck d Bob

5) What is the SI unit for entropy a joules b kelvin c joules/kelvin d kelvin/joule