Download presentation
Presentation is loading. Please wait.
Published byErik Carroll Modified over 9 years ago
1
Thermodynamics First and Second Laws of Thermodynamics (Chapter 12) Internal energy and heat engine efficiency (Chapter 12) Specific and latent heats (Chapter 12) Gases and Kinetic Theory Molecular properties (Chapter 13) Heat transfer and expansion (Chapter 13) Pressure (Chapter 13)
2
Do Now: In your own words Define: ▪ Conduction ▪ Convection ▪ Radiation ▪ Heat ▪ Thermal Equilibrium ▪ Specific Heat ▪ Temperature In Class: What is happening when you hold a cold glass of water? ▪ Temperature ▪ Conduction ▪ Convection ▪ Radiation Heat Heat Transfer {Q = mCΔT} ▪ Thermal Equilibrium ▪ Tf = [m A C A T A + m B C B T B ] / [m A C A + m B C B ] Homework: Page 319: Practice Problems #’s 3 – 9 All
3
Convert F C K Page 316 – 317 Practice Problems 1 - 2
4
Heat Heat Transfer {Q = mCΔT} Glass of Water Page: 318 Specific Heat Example 1 Page 319 Practice Problem #3
5
A higher temperature object which is in contact with a lower temperature object will transfer heat to the lower temperature object. The objects will approach the same temperature, and in the absence of loss to other objects, they will then maintain a constant temperature. They are then said to be in thermal equilibrium. T f = [m A C A T A + m B C B T B ] / [m A C A + m B C B ]
6
Heat Capacity Melting and Freezing Heat Capacity Q = mCΔT Heat of FUSION Q = mH f Heat of VaporizationQ = mH v Lesson 2 In Class: Read Chap 12.2 Define Melting and Boiling Points Do Example 3 Homework : Page 322 – 325 #’s: 10 – 21 ALL
7
Thermodynamic Laws Lesson 3 In Class Zeroth Law: Thermal equilibrium First Law:ΔU = Q – Work Second Law:Entropy ΔS = Q / T Homework Homework : Page 328 – 331#’s: 22 – 33 ALL Do Now TEST: How much Energy will it take to melt 0.500 Kg of Ice at -5.00 degree Centigrade to bring it to Water at 20.0 degree C? TEST #2 TEST #2 A 10.0 Kg piece of ZINC at 71.0 degree C Is placed in a beaker of water containing 20.0 Kg of water at 10.0 degree C. What is the final temperature of the water and Zinc?
8
Do Now: Honors Warnings with Parents In Class: Mechanical Energy Thermal Energy Exchange A 2000.0 Kg roller coaster starts (from Rest) down a 59.4 meter hill (no friction). When it reaches the bottom it rolls out on a flat track and applies its brakes. The (8) brakes on the roller coaster are each made up of a carbon compound. Each Brake has a mass of 50.0 Kg (Specific heat of 800.0 J/Kg-K) and bring the coaster to a stop. How hot are the brakes is they started at 20.0 degrees C? Homework: Page 331 # 32 SFW 2012
9
Zeroth Law of Thermodynamics The "zeroth law" states that if two systems are at the same time in thermal equilibrium with a third system, they are in thermal equilibrium with each other.thermal equilibrium Lesson 3
10
First Law of Thermodynamics The first law of thermodynamics is the application of the conservation of Energy principle to heat and thermodynamic processes: Lesson 3
11
Second Law of Thermodynamics The 2 nd law of thermodynamics is a profound principle of nature which affects the way energy can be used. There are several approaches to stating this principle qualitatively. Here are some approaches to giving the basic sense of the principle. http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html#c2 Lesson 3
12
not Second Law of Thermodynamics Heat will not flow spontaneously from a cold object to a hot object. Second Law: Refrigerator Energy will not flow spontaneously from a low temperature object to a higher temperature object. This precludes a perfect refrigerator. The statements about refrigerators apply to air conditioners and heat pumps, which embody the same principles.. Lesson 3
13
Do Now: Originally a system had 8000J of thermal energy. 4000J of energy was taken from the system and used for work in a thermodynamic engine. “Ideally” how far could you lift a 100.0 kg object from the ground if that engine were 100% efficient? Homework: Page 337 – 338 #’s 54, 57, 59, 62, 63, 64,67, 71 What is the best efficiency of Romac’s F-150 4.6 L V-8 Engine that operates at a temperature of 250 degrees F on a warm spring day when the outside air temperature is 70 degrees F? In Class: Carnot Heat Engines Thermodynamic Engine Efficiency What is ENTROPY? Thermodynamic mechanical Work Page 336 #’s 36 – 44 All Tc = (5/9)*(Tf-32) Tf = (9/5)*Tc+32 Lesson 4
14
Heat Engine - Efficiency Lesson 4 Heat Engines are Everywhere.... Arrgh! Heat engines propel cars, trucks, motorcycles, trains and airplanes. They are used to generate electricity at coal- and gas- fired power generating facilities. Heat engines exist in nature as well.... in fact weather systems that transport thermal energy from equatorial regions can be though of as planetary-scale heat engines..
15
Heat Pumps - Refrigerators. Lesson 4 http://hyperphysics.phy- astr.gsu.edu/hbase/thermo/heatengcon. html#c1
16
How fast will it cool ? Mass of Water 151.2 g Initial Air Temp: 21.4 C Final Air Temp: 21.8 What is the specific heat of the water? How much energy was used to heat the water from 22.5 - 59.2 deg C? When will the water reach room temperature (21.6 deg C)? Heating Time min Temp C Cooling 022.5 - 125.7Heating 232.4Heating 340.8Heating 448.9Heating 558.3Heating 659.2Cooling 757.5Cooling 856.3Cooling 955Cooling 1053.8Cooling 1152.9Cooling 1252Cooling 1351.1Cooling 1450.3Cooling 1549.2Cooling Lesson 5
17
Thermo Review Homework: Thermo Summary Sheet Lesson 5 Heat Capacity Q = mCΔT Heat of FUSION Q = mH f Heat of VaporizationQ = mH v Carnot Cycle Efficiency = {T H - T C / T H } x 100 Thermal Equilibrium
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.