2. Heat and Temperature Section 1 Pages 420-426

3. temperature A measure of the average kinetic energy of the particles of an object

4. Kinetic Energy and Heat

5. Expansion Most objects expand when their temperature increases As temp rises, particles gain kinetic energy, move faster, and move farther apart causing expansion

6. thermometer An instrument that measures and indicates temperature Rely on expansion of a liquid –Alcohol –Mercury 77

7. Temperature Scales The main two we use everyday are Fahrenheit Celsius

8. A Third Important Scale is the Kelvin Scale

9. Kelvin Scale Based on absolute 0 Absolute zero is the lowest possible temp At absolute zero the kinetic energy of an object is zero Motion stops, can’t be colder than that

10. Celsius and Kelvin degrees are the same size Kelvin = Celsius + 273

11. First Law of Thermodynamics Energy that is transferred as a result of work, heat, or both is conserved This is also known as the Law of Conservation of Energy

12. Second Law of Thermodynamics Heat is always transferred from the warmer object to the colder one

13. Matter exists in four phases Solid Liquid Gas Plasma five

14. Change of Phase

15. Heat is measured in units called calories

16. Calorie One calorie is the amount of heat required to change the temperature of 1 gram of water 1ºC

18. Heat of Fusion Heat of Fusion--the amount of energy it takes to change any substance from solid to liquid (Ice to water) & vice versa For water--80 calories per gram

20. Heat of Vaporization Heat of Vaporization--the amount of energy required to change any substance from liquid to gas (and vice versa) for water For water--540 calories per gram

23. Energy is released when a change of phase takes place in this direction. Energy is absorbed when a change of phase takes place in this direction.

24. Three Methods of Heat Transfer Conduction Convection Radiation

25. Conduction Heat transfer between two objects that are touching or with one object 82

26. Convection Movement of matter due to differences in density that are caused by temperature variations Ex. oatmeal 83

27. Convection currents 83

28. Radiation Energy that is transferred as electromagnetic waves, such as visible light and infrared waves 84

29. Use this picture to describe the three methods of heat transfer

30. Heat and the Changing States of Matter Today we talk about how things heat up and cool off at different rates.

31. Heat makes most items expand Substances expand at different rates 80

32. Ball and Ring Demo This chapter we will do several labs around heat Let’s review some lab safety ! lab safety

33. Specific Heat Capacity The quantity of heat required to change the temperature of a unit mass of the substance by 1 degree.

34. Specific Heat Capacity

35. Conductors A material that conducts heat well and quickly Metals are good conductors

36. Insulators A material that minimizes the transfer of heat energy

37. Not all materials heat up and cool off at the same rate A Bimetal Bar is made of two metals sandwiched together One of the metals has a higher specific heat capacity so it heats up slower than the other metal The result is...

38. Lab precautions You will be near hot burners BE CAREFUL No loose clothing or long hair –You don’t have to cut your hair, just pull it back

39. Bimetal Bar Lab In this lab you will heat a bimetal bar Observe carefully what happens 81

41. Specific Heat Capacity The amount of heat required to raise a unit mass of a homogenous material 1K or 1° C in a specified way given constant pressure and volume The amount of heat required to raise a unit of a material 1K or 1°C Symbol for specific heat— c c= J/kg. K Energy = specific heat x mass x temperature change E = c m t 86

42. Film: Lab Safety Clothing hazards

43. Specific Heat Lab Aluminum Brass Steel Nickel Copper ? Which one will heat up fastest?

44. Specific Heat Capacity The amount of heat required to raise a unit mass of a homogenous material 1K or 1° C in a specified way given constant pressure and volume The amount of heat required to raise a unit of a material 1K or 1°C Symbol for specific heat— c c= J/kg. K Energy = specific heat x mass x temperature change E = c m t 86

45. Film: Lab Safety Clothing hazards

46. Specific Heat Lab Aluminum Brass Steel Nickel Copper ? Which one will heat up fastest?

47. Can demo When the can is heated the air inside is warmed It expands and flows out of the can Now there are fewer molecules in the can When you tip it in water, the greater pressure from the cold water causes it to implode

48. Thermometers use different methods Furnaces use bimetal strips –Use 2 metals that expand at different rates Digital thermometers –use changes in electrical current 80

49. . Water cools and heats up slowly. It has a high heat capacity. Most metals have a low heat capacity, they heat up rapidly. 75% of the Earth's surface is water so it helps moderate our temperatures

50. It also causes wind because of differential heating of Earth‘s surfaces. Hot air is less dense and rises, cool air rushes in beneath.

51. Specific Heat Capacity The quantity of heat required to change the temperature of a unit mass of the substance by 1 degree Celsius.

52. Specific Heat Capacity or Specific Heat The specific heat capacity of any substance is defined as the quantity of heat required to change the temperature of a unit mass of the substance by 1 degree. Form a hypothesis: Land will heat up faster than water.

53. LAB Thermal Inertia State the question: Does land or water heat up and cool down faster? Hypothesis Collect Information Results Analysis

54. Thermal inertia Land vs. water Water cools and heats up slowly. It has a high heat capacity. Most metals have a low heat capacity, they heat up rapidly.

55. 75% of the Earth's surface is water so it helps moderate our temperatures. It also causes wind because of differential heating of Earth's surfaces.

56. Sea breeze A sea breeze occurs during the day when air is heated up quickly over the land and rises. This causes the slower heating seawater to produce less updrafts and the air flows inward towards the land to fill the missing rising air from the land creating a sea breeze.

57. Land breeze A land breeze occurs during the night as the slower cooling seawater releases warm air and it rises. This rising causes the cooler air to flow from the land to the sea filling the rising air's place, creating a land breeze.

58. Thermodynamic Demos