Phys 221 SI Worksheet:
Heat
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Justin
Phys 221
Rosenberg
4/17/14
1. What are the three types of heat transfer? Explain each.
2. What is the formula describing the heat transfer for conduction? What is k?
3. What does the above equation tell you about conduction?
4. Consider a hot object and a cold object connected by a solid rod. For each of the
following questions, in which scenario does heat transfer faster?
a) (1) T_H=400k, T_C=100k (2) T_H=400k, T_C=200k. Rods are made of same
material of the same length, and area.
b) (1) rod is thicker and shorter than rod(2)
c) (1) the material of the rod has a higher thermal conductivity than (2)
d) (1) rod is twice as thick and twice as long as (2)
5. If it is 20 degrees C inside and 0 degrees C outside, what is the heat flow through a glass
window of area 0.3 square meters and thickness 0.5cm? (thermal conductivity of glass is
about 1 W/mK)
6. Now consider the same problem but with a double pane window with a .5cm gap of air
between the panes? (thermal conductivity of air is .024W/mK)
7. What is the equation for the rate of heat transfer for radiation?
8. What does the above equation tell you about radiation?
9. What is e? What is σ?
10. What is the rate of heat loss does a black body with area of 1.5m^2, and a temperature of
100 degrees Celsius in a 0 degree Celsius room lose?
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