College Physics (10th Edition)
10th Edition
ISBN: 9780321902788
Author: Hugh D. Young, Philip W. Adams, Raymond Joseph Chastain
Publisher: PEARSON
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Textbook Question
Chapter 14, Problem 74GP
Hot air in a physics lecture. (a) A typical student listening attentively to a physics lecture has a heat output of 100 W. How much heat energy does a class of 90 physics students release into a lecture hall over the course of a 50 min lecture? (b) Assume that all the heat energy in part (a) is transferred to the 3200 m3 of air in the room. The air has a specific heat of 1020 J/(kg·K) and a density of 1.20 kg/m2. If none of the heat escapes and the air-conditioning system is off, how much will the temperature of the air in the room rise during the 50 min lecture? (c) If the class is taking an exam, the heat output per student rises to 280 W. What is the temperature rise during 50 min in this case?
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Students have asked these similar questions
a) A typical student listening
attentively to a physics lecture has
a heat output of 108 W. How
much heat energy does a class of
95 physics students release into a
lecture hall over the course of a
50 min lecture? Express your
answer in joules.
b) Assume that all the heat energy
in part A is transferred to the 3204
m3 of air in the room. The air has
a specific heat of 1020 J/(kg.K)
and a density of 1.20 kg/m3. If
none of the heat escapes and the
air-conditioning system is off, how
much will the temperature of the
air in the room rise during the 50
min lecture? Express your answer
in Celsius degrees.
c) If the class is taking an exam,
the heat output per student rises
to 285 W. What is the temperature
rise during 50 min in this case?
Express your answer in Celsius
degrees.
A ceiling area of 100 square meters consisting of four materials. The
thermal insulation value of these materials from top to bottom is (0.6, 50,
0.7 and 0.45) square meters per watt per degree, respectively. If the
external temperature is 5 degrees and the internal temperature is 20
degrees, what What is the speed of heat transfer through the wall?
Imagine that a hypothetical life form is discovered on our moon and transported to Earth. On a hot day, this life form begins to
sweat, and it is determined that the heat of vaporization of its sweat is 339 cal/g. The scientist observing the extraterrestrial
life form also begins to sweat. The heat of vaporization of the scientist's sweat is 580 cal/g at the skin's surface.
If both the extraterrestrial life form and the scientist lose 259 g of sweat over the course of one hour, calculate the heat lost by
each body from the vaporization of sweat.
extraterrestrial:
cal
human scientist:
cal
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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