Physics II PHY 202/222 Temp, Heat & Gas Laws 452 South Anderson Road Rock Hill, SC

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

Beiser Chapter 18 - Heat Beiser p.213

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

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

Celsius Kelvin (Celsius +273) Fahrenheit Water freezes 0oC0oC273 K32 o F Water boils 100 o C373 K212 o F T Beiser p.214 Temperature Scales

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

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

C J/(kg o C) cal/(g o C) or kcal/(kg o C) Water Ice Wood Aluminum Glass Iron Copper How much energy does it take to change the temperature of the material. Beiser p.214 Specific Heat Capacity

Beiser p Change of State

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

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

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

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Beiser p.224 Beiser Chapter 19 Thermal Expansion

LOLO ΔLΔL ΔTΔT Beiser p.224 Linear Expansion

VOVO V = V O + ΔV ΔTΔT Beiser p.224 Volume Expansion

V1V1 ΔT= 0 V2V2 P1P1 P2P2 As volume goes up, pressure goes down to keep the product constant. Beiser p.226 Boyle’s Law

V1V1 Δp = 0 V2V2 T1T1 T2T2 As volume goes up, temperature drops. T must be in K! Beiser p.227 Charles’s Law

V1V1 V2V2 P1P1 P2P2 Volume, pressure and temperature are all related by the Ideal Gas Law. Beiser p.228 T1T1 T2T2 The Ideal Gas Law

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Beiser p.259 Chapter 22 Heat Transfer

Beiser p.259 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.260 Thermal Resistance Material k (W/m o C) Air.026 Wood0.12 Water0.61 Glass0.8 Iron80.3 Aluminum237 Copper398 Silver427

Beiser p.261 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.262 Radiation Heating by energy from electro-magnetic waves. R rate of radiation P power emitted A surface area T temperature σ = 5.67 E-8 W/(m 2 K 4 ) e emissivity 0 total reflection 1 blackbody/total absorption 0<e<1 will be given Stefan-Boltzmann Law

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