College Physics (10th Edition)
10th Edition
ISBN: 9780321902788
Author: Hugh D. Young, Philip W. Adams, Raymond Joseph Chastain
Publisher: PEARSON
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Chapter 14, Problem 57P
(a)
To determine
The temperature at the fat–inner fur boundary.
(b)
To determine
The thickness of the air layer.
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The thermal conductivities of human tissues vary greatly. Fat and skin have conductivities of about 0.20 W/m . K and 0.020 W/m . K, respectively, while other tissues inside the body have conductivities of about 0.50 W/m . K. Assume that between the core region of the body and the skin surface lies a skin layer of 1.0 mm, fat layer of 0.50 cm, and 3.2 cm of other tissues. (a) Find the R-factor for each of these layers, and the equivalent R-factor for all layers taken together, retaining two digits. (b) Find the rate of energy loss when the core temperature is 37°C and the exterior temperature is 0°C. Assume that both a protective layer of clothing and an insulating layer of unmoving air are absent, and a body area of 2.0 m2.
The thermal conductivities of human tissues vary greatly. Fat and skin have conductivities of about 0.20 W/m · K and 0.020 w/m · K respectively, while other tissues inside the body
have conductivities of about 0.50 W/m · K. Assume that between the core region of the body and the skin surface lies a skin layer of 1.0 mm, fat layer of 0.50 cm, and 3.2 cm of other
tissues.
(a) Find the R-factor for each of these layers, and the equivalent R-factor for all layers taken together, retaining two digits.
m² - K/W
Rskin
m² . K/W
Rfat
m² - K/W
Rtissue
|m² - K/W
R
(b) Find the rate of energy loss when the core temperature is 37°C and the exterior temperature is 0°C. Assume that both a protective layer of clothing and an insulating layer of
unmoving air are absent, and a body area of 2.0 m2.
The thermal conductivities of human tissues vary greatly. Fat and skin have conductivities of about 0.20 W/m · K and 0.020 W/m · K respectively, while other tissues inside the body have conductivities of about 0.50 W/m · K. Assume that between the core region of the body and the skin surface lies a skin layer of 1.0 mm, fat layer of 0.50 cm, and 3.2 cm of other tissues.
(a) Find the R-factor for each of these layers, and the equivalent R-factor for all layers taken together, retaining two digits.
Rskin
m2 · K/W
Rfat
m2 · K/W
Rtissue
m2 · K/W
R
m2 · K/W
(b) Find the rate of energy loss when the core temperature is 37°C and the exterior temperature is 0°C. Assume that both a protective layer of clothing and an insulating layer of unmoving air are absent, and a body area of 2.0 m2. W
Chapter 14 Solutions
College Physics (10th Edition)
Ch. 14 - When a block with a hole in it is heated, why...Ch. 14 - You have a drink that you want to cool off. You...Ch. 14 - A thermostat for controlling household heating...Ch. 14 - Why is it sometimes possible to loosen caps on...Ch. 14 - To raise the temperature of an object, must you...Ch. 14 - Prob. 6CQCh. 14 - If you have wet hands and pick up a piece of metal...Ch. 14 - If you add heat slowly to ice at 0C, why doesnt...Ch. 14 - Prob. 9CQCh. 14 - A person pours a cup of hot coffee, intending to...
Ch. 14 - If you put your hand into boiling water at 212F,...Ch. 14 - You are going away for the weekend and plan to...Ch. 14 - Why is snow, which is made up of ice crystals, a...Ch. 14 - A cold block of metal feels colder than a block of...Ch. 14 - Prob. 15CQCh. 14 - If heat Q is required to increase the temperature...Ch. 14 - Prob. 2MCPCh. 14 - If an amount of heat Q is needed to increase the...Ch. 14 - if you mix 100 g of ice at 0C with 100 g of...Ch. 14 - Prob. 5MCPCh. 14 - Prob. 6MCPCh. 14 - A thin metal rod expands 1.5 mm when its...Ch. 14 - Prob. 8MCPCh. 14 - Prob. 9MCPCh. 14 - The thermal conductivity of concrete is 0.80...Ch. 14 - The graph in Figure 14.24 shows the temperature as...Ch. 14 - For the sample in the preceding question, what...Ch. 14 - (a) While vacationing in Europe, you feel sick and...Ch. 14 - Temperatures in biomedicine. (a) Normal body...Ch. 14 - (a) On January 22, 1943. the temperature in...Ch. 14 - Inside the earth and the sun. (a) Geophysicists...Ch. 14 - (a) At what temperature do the Fahrenheit and...Ch. 14 - Prob. 6PCh. 14 - The Eiffel Tower in Paris is 984 ft tall and is...Ch. 14 - A steel bridge is built in the summer when its...Ch. 14 - A metal rod is 40.125 cm long at 20.0C and 40.148...Ch. 14 - A steel bar and a copper bar have the same length...Ch. 14 - An underground tank with a capacity of 1700 L...Ch. 14 - A copper cylinder is initially at 20.0C. At what...Ch. 14 - An aluminum sphere has a diameter of 30.00 cm at...Ch. 14 - The outer diameter of a glass jar and the inner...Ch. 14 - A glass flask whose volume is 1000.00 cm3 at 0.0C...Ch. 14 - Ensuring a tight fit. Aluminum rivets used in...Ch. 14 - The markings on an aluminum ruler and a brass...Ch. 14 - Prob. 18PCh. 14 - One of the moving parts of an engine contains 1.60...Ch. 14 - In an effort to stay awake for an all-night study...Ch. 14 - Prob. 21PCh. 14 - Prob. 22PCh. 14 - You are given a sample of metal and asked to...Ch. 14 - Prob. 24PCh. 14 - You add 5000 J of heat to a piece of iron and you...Ch. 14 - Prob. 26PCh. 14 - A 15.0 g bullet traveling horizontally at 865 m/s...Ch. 14 - Prob. 28PCh. 14 - A technician measures the specific heat of an...Ch. 14 - Prob. 30PCh. 14 - Consult Table 14.4. (a) How much heat is required...Ch. 14 - A blacksmith cools a 1.20 kg chunk of iron,...Ch. 14 - Treatment for a stroke. One suggested treatment...Ch. 14 - A container holds 0.550 kg of ice at 15.0C. The...Ch. 14 - On a cold winter day, a 1 kg aluminum sphere at an...Ch. 14 - Evaporative cooling. The evaporation of sweat is...Ch. 14 - Prob. 37PCh. 14 - How much heat is required to convert 12.0 g of ice...Ch. 14 - Steam burns vs. water burns. What is the amount of...Ch. 14 - Bicycling on a warm day. If the air temperature is...Ch. 14 - Overheating. (a) By how much would the body...Ch. 14 - You have 750 g of water at 10.0C in a large...Ch. 14 - Prob. 43PCh. 14 - A copper pot with a mass of 0.500 kg contains...Ch. 14 - In a physics lab experiment, a student immersed...Ch. 14 - A laboratory technician drops an 85.0 g solid...Ch. 14 - The specific heat of sulfur is 750 J/(kgK), and...Ch. 14 - An insulated beaker with negligible mass contains...Ch. 14 - A Styrofoam bucket of negligible mass contains...Ch. 14 - A slab of a thermal insulator with a...Ch. 14 - You are asked to design a cylindrical steel rod...Ch. 14 - Conduction through the skin. The blood plays an...Ch. 14 - A pot with a steel bottom 8.50 mm thick rests on a...Ch. 14 - A carpenter builds an exterior house wall with a...Ch. 14 - A picture window has dimensions of 1.40 m 2.50 m...Ch. 14 - One end of an insulated metal rod is maintained at...Ch. 14 - Prob. 57PCh. 14 - A box-shaped coal-burning stove has exhausted most...Ch. 14 - How large is the sun? By measuring the spectrum of...Ch. 14 - Basal metabolic rate. The basal metabolic rate is...Ch. 14 - The emissivity of tungsten is 0.35. A tungsten...Ch. 14 - A spherical pot of hot coffee contains 0.75 L of...Ch. 14 - Prob. 63GPCh. 14 - Prob. 64GPCh. 14 - Global warming. As the earth warms, sea level will...Ch. 14 - A Foucault pendulum consists of a brass sphere...Ch. 14 - On-demand water heaters. Conventional hot-water...Ch. 14 - Prob. 68GPCh. 14 - Shivering. You have no doubt noticed that you...Ch. 14 - A steel ring with a 2.5000 in. inside diameter at...Ch. 14 - Pasta time! You are making pesto for your pasta...Ch. 14 - A copper calorimeter can with mass 0.100 kg...Ch. 14 - A 0.4 kg piece of ice at 10C is dropped from a...Ch. 14 - Hot air in a physics lecture. (a) A typical...Ch. 14 - The ship of the desert. Camels require very little...Ch. 14 - A worker pours 1.250 kg of molten lead at a...Ch. 14 - A thirsty nurse cools a 2.00 L bottle of a soft...Ch. 14 - One experimental method of measuring an insulating...Ch. 14 - The icecaps of Greenland and Antarctica contain...Ch. 14 - The effect of urbanization on plant growth. A...Ch. 14 - Basal metabolic rate. The energy output of an...Ch. 14 - A thermos for liquid helium. A physicist uses a...Ch. 14 - Prob. 83PPCh. 14 - Prob. 84PPCh. 14 - In another experiment, you place a layer of this...Ch. 14 - To measure the specific heat in the liquid phase...
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