Physics II PHY 202/222 Temp, Heat & Gas Laws

1. Physics IIPHY 202/222Temp, Heat & Gas Laws 452 South Anderson Road Rock Hill, SC 29730 www.yorktech.com

2. Temp, Heat & Gas Laws Test 2 • Beiser Chapters 18, 19 & 22 • - Multiple Choice – Odd • - Supplementary Problems - Odd • Browne Chapter 17 for PHY 221 Students • - Supplementary Problems - 4,5,10,14

3. Beiser Chapter 18 - Heat Beiser p.213

4. Stuff Remember: All matter is composed of molecules which are moving rapidly. Since these molecules are moving and have mass, they have kinetic energy! Beiser p.213

5. Definitions • Internal Energy – sum of the kinetic energies of molecules of matter • Temperature – measure of average kinetic energy of molecules • Heat – internal energy in transit • Thermometer – a device to measure temperature Beiser p.213-4

6. Temperature Scales T Beiser p.214

7. Heat (Internal energy in transit) Q Units of heat • Joule - SI unit • Calorie (cal) - heat needed to raise 1 g of water 1oC • Kilocalorie (kcal) – heat needed to raise 1 kg of water 1oC (same as calorie in food info) • 1 kcal = 1000 cal Beiser p.214

8. Heat Q “British” Units of heat • British Thermal Units (BTU) – heat needed to raise 1 lb of water 1oF • 1 kcal = 3.97 BTU = 4185 J Beiser p.214

9. Specific Heat Capacity C How much energy does it take to change the temperature of the material. Beiser p.214

10. Change of State Beiser p.216-7

11. Calorimetry • Sensible heat – adding heat raises temperature • Latent heat – adding heat changes state Beiser p.215-7

12. Calorimetry example • How much heat will it take to melt 2 kg of ice? • How much heat will it take to raise the temperature of 2 kg of water by 17o C? • How much heat will it take to melt 2 kg of ice and raise the temperature to 17o C? 670 kJ 142 kJ Beiser p.215

13. Mixing problem Add 200 g of iron at 100oC to 600 g of water at 20oC. Find the final temperature. Beiser p.216

14. 18.4

15. 18.6

16. 18.8

17. 18.10

18. 18.12

19. 18.14

20. 18.16

21. 18.18

22. 18.20

23. 18.22

24. 18.24

25. Beiser Chapter 19Thermal Expansion Beiser p.224

26. Linear Expansion LO ΔL ΔT Beiser p.224

27. Volume Expansion VO V = VO + ΔV ΔT Beiser p.224

28. Boyle’s Law V2 V1 ΔT= 0 P2 P1 As volume goes up, pressure goes down to keep the product constant. Beiser p.226

29. Charles’s Law V2 V1 Δp = 0 T2 T1 As volume goes up, temperature drops. T must be in K! Beiser p.227

30. The Ideal Gas Law V2 V1 P1 P2 T1 T2 Volume, pressure and temperature are all related by the Ideal Gas Law. Beiser p.228

31. 19.2

32. 19.4

33. 19.6

34. 19.8

35. 19.14

36. 19.16

37. Chapter 22Heat Transfer Beiser p.259

38. Rate of Heat Conduction Heating by contact/collisions between molecules. Q heat t time k thermal conductivity - look up A cross section area ΔT ΔT from 1 hot to cold side d length/thickness of material Beiser p.259

39. Thermal Resistance Beiser p.260

40. Convection Heating by motion of a hot fluid. Q heat t time h factor will be given A area of contact hot to fluid ΔT ΔT between hot and fluid Beiser p.261

41. Radiation Heating by energy from electro-magnetic waves. Stefan-Boltzmann Law R rate of radiation P power emitted A surface area T temperature σ = 5.67 E-8 W/(m2K4) e emissivity 0 total reflection 1 blackbody/total absorption 0<e<1 will be given Beiser p.262

42. 22.4

43. 22.6

44. 22.10