You have smooth slabs of Titanium (Ti), polycrystalline silica (SiO2), and atactic PS. Rank them from highest to lowest: Thermal conductivity (k) Heat capacity (Cp) Energy band gap (Eg) Thermal expansion coefficient (a) Transparency Resistivity

You have smooth slabs of Titanium (Ti), polycrystalline silica (SiO2), and atactic PS. Rank them from highest to lowest: Thermal conductivity (k) Heat capacity (Cp) Energy band gap (Eg) Thermal expansion coefficient (a) Transparency Resistivity

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.73P: Estimate the R-values for a 5-cm-thick fiberglass board and a 2.5-cm-thick polyurethane foam layer....

See similar textbooks

Similar questions

The thermal conductivity of fibreglass insulation at 67F is 0.02 Btu/h ft F. What is its value in SI units?
Estimate the R-values for a 5-cm-thick fiberglass board and a 2.5-cm-thick polyurethane foam layer. Then, compare their respective conductivity-times-density products if the density for fiberglass is 50kg/m3 and the density of polyurethane is 30kg/m3. Use the units given in Figure 1.31.
To determine the thermal conductivity of a structural material, a large 15-cm-thick slab of the material is subjected to a uniform heat flux of 2500 W/m2 while thermocouples embedded in the wall at 2.5 cm. intervals are read over a period of time. After the system had reached equilibrium, an operator recorded the thermocouple readings shown below for two different environmental conditions: Distance from the Surface (cm) Temperature (C) Test 1 0 40 5 65 10 97 15 132 Test 2 0 95 5 130 10 168 15 208 From these data, determine an approximate expression for the thermal conductivity as a function of temperature between 40 and 208C.
Using the information in Problem 1.22, estimate the ambient air temperature that could cause frostbite on a calm day on the ski slopes. 1.22 In order to prevent frostbite to skiers on chair lifts, the weather report at most ski areas gives both an air temperature and the wind-chill temperature. The air temperature is measured with a thermometer that is not affected by the wind. However, the rate of heat loss from the skier increases with wind velocity, and the wind-chill temperature is the temperature that would result in the same rate of heat loss in still air as occurs at the measured air temperature with the existing wind. Suppose that the inner temperature of a 3-mm-thick layer of skin with a thermal conductivity of 0.35W/mKis35C and the air temperature is 20C. Under calm ambient conditions the heat transfer coefficient at the outer skin surface is about 20W/m2K (see Table 1.4), but in a 40-mph wind it increases to 75W/m2K. If frostbite occurs when the skin temperature drops to about 10C, do you advise the skier to wear a face mask? What is the skin temperature drop due to the wind?
1.3 A furnace wall is to be constructed of brick having standard dimensions of Two kinds of material are available. One has a maximum usable temperature of 1040°C and a thermal conductivity of 1.7 W/(m K), and the other has a maximum temperature limit of 870°C and a thermal conductivity of 0.85 W/(m K). The bricks have the same cost and are laid in any manner, but we wish to design the most economical wall for a furnace with a temperature of 1040°C on the hot side and 200°C on the cold side. If the maximum amount of heat transfer permissible is 950 , determine the most economical arrangement using the available bricks.
After the sinking of RMS Titanic, US operated the International Ice patrol with the purpose of monitoring the presence and movements of icebergs in the Atlantic and Arctic oceans. Once, they observed a unique tabular iceberg in a form of a rectangle (250 km x 50 km x 300 m). How many years would it take to melt the iceberg solely by heat from the sun if the ice absorbs a mean of 98 J/m2 -s, 12.5 hrs per day? Note: the exposed area for heating is 250 km x 50 km and the density is 920 kg/m3 . This is my solution.
For a specified heat input and a given volume which material will have the smallest tempera- ture rise (Use data book if necessary) (a) steel (b) aluminium (c) water (d) copper. When a hot metal piece is left to cool in air the time rate of cooling of the outer layer will be (a) slower at start and faster near the end (b) faster at start and slower near the end (c) both rates will be the same (d) this will depend on the material. (viii) A thin black plate at temperature T receives radiation from a surface at Temperature T1 and radiates to a surface at T2. If all surfaces are black at steady state (a) (T1 – T) > (T – T2) (b) (T1 – T) < (T – T2) (c) (T1 – T) = (T – T2) (d) can be any one of a, b or c. (ix) The temperature profile (in) a slab initially at a constant temperature and then allowed to cool by convection for a short time will be as shown in Fig : (a) E1.2a (b) E1.2b (c) E1.2c (d) E1.2d. Ti
R Value: Wall: 0.961m2k/w Floor: 0.676m2k/w Roof: 0.7465m2k/w In a table format show with calculations and research how much money you can save by installing a 115mm layer of insulation (R2.9) in your walls, floor and ceiling over a 5 and 10 year period. Consider the capital costs. Hint: State the current R value of each component. Convert to U value. Calculate new R value of each component (walls, floor and ceiling). Convert to U value. Use Q(W)=A*(change in U)*temperature change. Determine price for installation of new insulation. Determine price saved based on less heat loss through each component separately, then add all values together, and calculate per 5 years and per 10 years. Present all of this information in a table. You do not need to draw any diagrams, simply add the R value in series with your current components R values. Assume the energy cost is 25 cents kWh
1. Choose the material that is brittle, a poor thermal conductor, a good thermal insulator, and can withstand high temperatures. a. Ceramics b. Composites c. Polymers d. Metals 2. Choose the substance with the greatest surface tension. a. C9H20 b. C12H26 c. C6H14 d. C24H50 3. Condensation polymers A. Are deposited in molds by condensing vapors B. Also release a small molecule such as water when they are formed C. Usually are made from monomers containing one or more C=C bonds D. None of the Above
Solve for interface temperatures. Given: heat transfer due to radiation= 507.415 W/m2
After the sinking of RMS Titanic, US operated the International Ice patrol with the purpose of monitoring the presence and movements of icebergs in the Atlantic and Arctic oceans. Once, they observed a unique tabular iceberg in a form of a rectangle (250 km x 50 km x 300 m). The sun is the only source of heat and the ice absorbs a mean of 98 J/m2-s, 12.5 hrs per day. The exposed area for heating is 250 km x 50 km and the density is 920 kg/m3. What is the total mass of the iceberg? Express answer in kg and in scientific notation with two decimal places. To input: if the answer is 4.78x1025, input 4.78e25.
After the sinking of RMS Titanic, US operated the International Ice patrol with the purpose of monitoring the presence and movements of icebergs in the Atlantic and Arctic oceans. Once, they observed a unique tabular iceberg in a form of a rectangle (250 km x 50 km x 300 m). The sun is the only source of heat and the ice absorbs a mean of 98 J/m2-s, 12.5 hrs per day. The exposed area for heating is 250 km x 50 km and the density is 920 kg/m3. How much heat does the exposed heating area absorb per day? Express answer in J/day and in scientific notation with four decimal places. To input: if the answer is 4.7834x1025, input 4.7834e25.