Physics II PHY 202222 Temp, Heat

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Physics II PHY 202/222 Temp, Heat Gas Laws

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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
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Beiser Chapter 18 - Heat
Beiser p.213
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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
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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
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Temperature Scales
T
Beiser p.214
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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
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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
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Specific Heat Capacity
C
How much energy does it take to change the
temperature of the material.
Beiser p.214
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Change of State
Beiser p.216-7
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Calorimetry

• Sensible heat
• adding heat raises temperature
• Latent heat
• adding heat changes state

Beiser p.215-7
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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
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Mixing problem

• Add 200 g of iron at 100oC to 600 g of water at
  20oC. Find the final temperature.

Beiser p.216
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18.4
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18.6
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18.8
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18.10
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18.12
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18.14
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18.16
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18.18
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18.20
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18.22
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18.24
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Beiser Chapter 19Thermal Expansion
Beiser p.224
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Linear Expansion
LO
?L
?T
Beiser p.224
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Volume Expansion
VO
V VO ?V
?T
Beiser p.224
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Boyles Law
V2
V1
?T 0
P2
P1
As volume goes up, pressure goes down to keep the
product constant.
Beiser p.226
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Charless Law
V2
V1
?p 0
T2
T1
As volume goes up, temperature drops. T must be
in K!
Beiser p.227
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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
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19.2
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19.4
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19.6
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19.8
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19.14
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19.16
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Chapter 22Heat Transfer
Beiser p.259
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Rate of Heat Conduction
Heating by contact/collisions between molecules.
Q heat t time k thermal conductivity - look up A
cross section area ?T ?T from 1 hot to cold
side d length/thickness of material
Beiser p.259
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Thermal Resistance
Beiser p.260
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Convection
Heating by motion of a hot fluid.
Q heat t time h factor will be given A area of
contact hot to fluid ?T ?T between hot and fluid
Beiser p.261
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Radiation
Heating by energy from electro-magnetic waves.
Stefan-Boltzmann Law
R rate of radiation P power emitted A surface
area T temperature s 5.67 E-8 W/(m2K4) e
emissivity 0 total reflection 1
blackbody/total absorption 0ltelt1 will be
given
Beiser p.262
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22.4
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22.6
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22.10