College Physics: A Strategic Approach (3rd Edition)
3rd Edition
ISBN: 9780321879721
Author: Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher: PEARSON
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Textbook Question
Chapter 12, Problem 91GP
A 68 kg woman cycles at a constant 15 km/h. All of the
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Alligators and other reptiles don’t use enough metabolic energy to keep their body temperatures constant. They cool off at night and must warm up in the sun in the morning. Suppose a 300 kg alligator with an early-morning bodytemperature of 25°C is absorbing radiation from the sun at a rate of 1200 W. How long will the alligator need to warm up to a more favorable 30°C? (Assume that the specific heat of the reptilian body is the same as that of the mammalian body.)
Overall, 80% of the energy used by the body must be eliminated as excess thermal energy and needs to be dissipated. The mechanisms of elimination are radiation, evaporation of sweat (2,430 kJ/kg),
evaporation from the lungs (38 kJ/h), conduction, and convection.
A person working out in a gym has a metabolic rate of 2,500 kJ/h. His body temperature is 37°C, and the outside temperature 28°C. Assume the skin has an area of 2.0 m2 and emissivity of 0.97.
(0 = 5.6696 x 10-8 W/m2 . K4)
(a) At what rate is his excess thermal energy dissipated by radiation? (Enter your answer to at least one decimal place.)
W
(b) If he eliminates 0.41 kg of perspiration during that hour, at what rate is thermal energy dissipated by evaporation of sweat? (Enter your answer to at least one decimal place.)
w
(c) At what rate is energy eliminated by evaporation from the lungs? (Enter your answer to at least one decimal place.)
w
(d) At what rate must the remaining excess energy be eliminated through conduction and…
Overall, 80% of the energy used by the body must be eliminated as excess thermal energy and needs to be dissipated. The
mechanisms of elimination are radiation, evaporation of sweat (2,430 kJ/kg), evaporation from the lungs (38 kJ/h),
conduction, and convection.
A person working out in a gym has a metabolic rate of 2,500 kJ/h. His body temperature is 37°C, and the outside
temperature 22°C. Assume the skin has an area of 2.0 m2 and emissivity of 0.97. (o = 5.6696 × 10-8 w/m2 · K4)
(a) At what rate is his excess thermal energy dissipated by radiation? (Enter your answer to at least one decimal
place.)
1.8e2
W
(b) If he eliminates 0.44 kg of perspiration during that hour, at what rate is thermal energy dissipated by
evaporation of sweat? (Enter your answer to at least one decimal place.)
3.0e2
W
(c) At what rate is energy eliminated by evaporation from the lungs? (Enter your answer to at least one decimal
place.)
10.6
W
(d) At what rate must the remaining excess energy be eliminated…
Chapter 12 Solutions
College Physics: A Strategic Approach (3rd Edition)
Ch. 12 - Which has more mass, a mole of Ne gas or a mole of...Ch. 12 - If you launch a projectile upward with a high...Ch. 12 - Prob. 3CQCh. 12 - If you buy a sealed bag of potato chips in Miami...Ch. 12 - If you double the typical speed of the molecules...Ch. 12 - Two gases have the same number of molecules per...Ch. 12 - a. Which contains more particles, a mole of helium...Ch. 12 - If the temperature T of an ideal gas doubles, by...Ch. 12 - A bottle of helium gas and a bottle of argon gas...Ch. 12 - A gas cylinder contains 1.0 mol of helium at a...
Ch. 12 - Prob. 11CQCh. 12 - Prob. 12CQCh. 12 - What is the maximum amount of work that a gas can...Ch. 12 - You need to precisely measure the dimensions of a...Ch. 12 - A common trick for opening a stubborn lid on a jar...Ch. 12 - Your cars radiator is made of steel and is filled...Ch. 12 - Materials A and B have equal densities, but A has...Ch. 12 - Prob. 18CQCh. 12 - You need to raise the temperature of a gas by 10C....Ch. 12 - A sample of ideal gas is in a cylinder with a...Ch. 12 - A student is heating chocolate in a pan on the...Ch. 12 - If you bake a cake at high elevation, where...Ch. 12 - The specific heat of aluminum is higher than that...Ch. 12 - A student is asked to sketch a pV diagram for a...Ch. 12 - In some expensive cookware, the pot is made of...Ch. 12 - If you live somewhere with cold, clear nights, you...Ch. 12 - Prob. 27MCQCh. 12 - Prob. 28MCQCh. 12 - A gas is compressed by an isothermal process that...Ch. 12 - Prob. 30MCQCh. 12 - Prob. 31MCQCh. 12 - Prob. 32MCQCh. 12 - Prob. 33MCQCh. 12 - Prob. 34MCQCh. 12 - 100 g of ice at 0C and 100 g of steam at 100C...Ch. 12 - Suppose the 600 W of radiation emitted in a...Ch. 12 - Prob. 37MCQCh. 12 - Prob. 38MCQCh. 12 - Prob. 1PCh. 12 - How many grams of water (H2O) have the same number...Ch. 12 - Prob. 3PCh. 12 - How many cubic millimeters (mm3) are in 1 L?Ch. 12 - Prob. 5PCh. 12 - Prob. 6PCh. 12 - An ideal gas is at 20C. The gas is cooled,...Ch. 12 - An ideal gas at 0C consists of 1.0 1023 atoms. 10...Ch. 12 - An ideal gas at 20C consists of 2.2 1022 atoms....Ch. 12 - Dry ice is frozen carbon dioxide. If you have 1.0...Ch. 12 - Prob. 11PCh. 12 - Prob. 12PCh. 12 - Prob. 13PCh. 12 - When you stifle a sneeze, you can damage delicate...Ch. 12 - Prob. 15PCh. 12 - Mars has an atmosphere composed almost entirely of...Ch. 12 - 3.0 mol of gas at a temperature of 120C fills a...Ch. 12 - The lowest pressure ever obtained in a laboratory...Ch. 12 - Helium has the lowest condensation point of any...Ch. 12 - A cylinder contains 3.0 L of oxygen at 300 K and...Ch. 12 - A gas with initial conditions pi, Vi, and Ti...Ch. 12 - 0.10 mol of argon gas is admitted to an evacuated...Ch. 12 - 0.10 mol of argon gas is admitted to an evacuated...Ch. 12 - 0.10 mol of argon gas is admitted to an evacuated...Ch. 12 - 0.0040 mol of gas undergoes the process shown in...Ch. 12 - 0.0040 mol of gas follows the hyperbolic...Ch. 12 - A gas with an initial temperature of 900C...Ch. 12 - How much work is done on the gas in the process...Ch. 12 - It is possible to make a thermometer by sealing...Ch. 12 - A 1.0 cm3 air bubble is released from the sandy...Ch. 12 - A weather balloon rises through the atmosphere,...Ch. 12 - A straight rod consists of a 1.2-cm-long piece of...Ch. 12 - The length of a steel beam increases by 0.73 mm...Ch. 12 - The length of a steel beam increases by 0.73 mm...Ch. 12 - A circular hole in a steel plate is 2.000 cm in...Ch. 12 - At 20C, the hole in an aluminum ring is 2.500 cm...Ch. 12 - The temperature of an aluminum disk is increased...Ch. 12 - Prob. 38PCh. 12 - How much heat is needed to change 20 g of mercury...Ch. 12 - a. 100 J of heat energy are transferred to 20 g of...Ch. 12 - Prob. 41PCh. 12 - Prob. 42PCh. 12 - Alligators and other reptiles dont use enough...Ch. 12 - When air is inhaled, it quickly becomes saturated...Ch. 12 - Prob. 45PCh. 12 - What minimum heat is needed to bring 100 g of...Ch. 12 - 30 g of copper pellets are removed from a 300C...Ch. 12 - A copper block is removed from a 300C oven and...Ch. 12 - A 750 g aluminum pan is removed from the stove and...Ch. 12 - A 500 g metal sphere is heated to 300C, then...Ch. 12 - Brewed coffee is often too hot to drink right...Ch. 12 - Native Americans boiled water by adding very hot...Ch. 12 - Marianne really likes coffee, but on summer days...Ch. 12 - If a person has a dangerously high fever,...Ch. 12 - A container holds 1.0 g of argon at a pressure of...Ch. 12 - A container holds 1.0 g of oxygen at a pressure of...Ch. 12 - What is the temperature change of 1.0 mol of a...Ch. 12 - Prob. 58PCh. 12 - Adding 150 J of heat to 0.50 mol of a monatomic...Ch. 12 - Heating 2.5 mol of neon in a rigid container...Ch. 12 - A 1.8-cm-thick wood floor covers a 4.0 m 5.5 m...Ch. 12 - A stainless-steel-bottomed kettle, its bottom 24...Ch. 12 - What is the greatest possible rate of energy...Ch. 12 - What is the greatest possible rate of energy...Ch. 12 - Seals may cool themselves by using thermal...Ch. 12 - Electronics and inhabitants of the International...Ch. 12 - The glowing filament in a lamp is radiating energy...Ch. 12 - If you lie on the ground at night with no cover,...Ch. 12 - A college student is working on her physics...Ch. 12 - Prob. 70GPCh. 12 - A rigid container holds 2.0 mol of gas at a...Ch. 12 - A 15-cm-diameter compressed-air tank is 50 cm...Ch. 12 - Prob. 73GPCh. 12 - Prob. 74GPCh. 12 - Suppose you take and hold a deep breath on a...Ch. 12 - On average, each person in the industrialized...Ch. 12 - On a cool morning, when the temperature is 15C,...Ch. 12 - Suppose you inflate your car tires to 35 psi on a...Ch. 12 - Prob. 79GPCh. 12 - An empty flask is placed in boiling water for a...Ch. 12 - 80 J of work are done on the gas in the process...Ch. 12 - How much work is done by the gas in the process...Ch. 12 - Prob. 83GPCh. 12 - 10 g of dry ice (solid CO2) is placed in a 10,000...Ch. 12 - Prob. 85GPCh. 12 - A 5.0-m-diameter garden pond holds 5.9 103 kg of...Ch. 12 - 0.030 mol of an ideal monatomic gas undergoes an...Ch. 12 - James Joule (after whom the unit of energy is...Ch. 12 - Prob. 89GPCh. 12 - Prob. 90GPCh. 12 - A 68 kg woman cycles at a constant 15 km/h. All of...Ch. 12 - Prob. 92GPCh. 12 - Prob. 93GPCh. 12 - What is the maximum mass of lead you could melt...Ch. 12 - An experiment measures the temperature of a 200 g...Ch. 12 - 10 g of aluminum at 200C and 20 g of copper are...Ch. 12 - A 100 g ice cube at 10C is placed in an aluminum...Ch. 12 - Prob. 98GPCh. 12 - Your 300 mL cup of coffee is too hot to drink when...Ch. 12 - A gas is compressed from 600 cm3 to 200 cm3 at a...Ch. 12 - An expandable cube, initially 20 cm on each side,...Ch. 12 - 0.10 mol of a monatomic gas follows the process...Ch. 12 - A monatomic gas follows the process 123 shown in...Ch. 12 - What are (a) the heat QH extracted from the hot...Ch. 12 - Homes are often insulated with fiberglass...Ch. 12 - The top layer of your goose down sleeping bag has...Ch. 12 - Suppose you go outside in your fiber-filled jacket...Ch. 12 - The surface area of an adult human is about 1.8...Ch. 12 - MCAT-Style Passage Problems Thermal Properties of...Ch. 12 - MCAT-Style Passage Problems Thermal Properties of...Ch. 12 - MCAT-Style Passage Problems Thermal Properties of...Ch. 12 - MCAT-Style Passage Problems Thermal Properties of...
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