Thermal Expansion ProblemT = 20 C L = 20.0 cm T = 600 C · Linear Expansion Coefficients (°C 1) L...
Transcript of Thermal Expansion ProblemT = 20 C L = 20.0 cm T = 600 C · Linear Expansion Coefficients (°C 1) L...
Thermal Expansion
1
Thermal Expansion
Explain why thermal expansion occurs & give examples.
Objectives
Calculate an objects thermal expansion or contraction of new length.
Explain differences in expansion of water.
Thermal Expansion
higher temp higher velocity requires more space
low temp slower velocity requires less space
Thermal Expansion of Water
As the temp. decreases from 4°C to 0°C, water expands - ice.
The maximum density of water (1.0 g/mL) occurs at 4°C.
Different materials expand at different amounts with the same temperature rise.
Solids (length)
Calculating Thermal Expansion
∆L = LO x α x ∆T
Aluminum 23 x 106
Brass 19 x 106
Copper 16 x 106
Glass 3.2 x 106
Gold 14 x 106
Iron (Soft) 12 x 106
Lead 29 x 106
Quartz .40 x 106
Steel 11 x 106
Linear Expansion Coefficients (°C 1)
Lo = 20.0 cm
T2 = 600 oC
T1 = 20 oCL = ?
Thermal Expansion Problem
Thermal Expansion
2
The Eiffel Tower, constructed in 1889 by Alexandre Eiffel, is an impressive latticework structure made of steel. If the tower is 301 m high on a 22 oC day, how much does its height decrease when the temperature cools to 0.0 oC?
Thermal Expansion Problem Thermal Expansion Joints
(Heat)
Bimetallic Stripα = 11 x 106 oC1
Steel
Brassα = 19 x 106 oC1
Bimetallic Stripα = 11 x 106 oC1
Steel
Brassα = 19 x 106 oC1
(Cool)
Thermostat Assignments . . .
Begin Chapter 21 Homework #16 20