Physics for Scientists and Engineers, Technology Update (No access codes included)
9th Edition
ISBN: 9781305116399
Author: Raymond A. Serway, John W. Jewett
Publisher: Cengage Learning
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Question
Chapter 20, Problem 20.68AP
(a)
To determine
The hourly rate at which water must evaporate from the skin of a person.
(b)
To determine
The fraction of water provided by fat metabolism to the jogger.
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The rate at which a resting person converts food energy is called one’s basal metabolic rate (BMR). Assume that the resulting internal energy leaves a person’s body by radiation and convection of dry air. When you jog, most of the food energy you burn above your BMR becomes internalenergy that would raise your body temperature if it were not eliminated. Assume that evaporation of perspiration is the mechanism for eliminating this energy. Suppose a person is jogging for “maximum fat burning,” converting food energy at the rate 400 kcal/h above his BMR, and putting out energy by work at the rate 60.0 W. Assume that the heat of evaporation of water at body temperature is equal to its heat of vaporization at 100°C. (a) Determine the hourly rate at which water must evaporate from his skin. (b) When you metabolize fat, the hydrogen atoms in the fat molecule are transferred to oxygen to form water. Assume that metabolism of 1.00 g of fat generates 9.00 kcal of energy and produces 1.00 g of…
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3.0e2
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10.6
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Chapter 20 Solutions
Physics for Scientists and Engineers, Technology Update (No access codes included)
Ch. 20 - Prob. 20.1QQCh. 20 - Suppose the same process of adding energy to the...Ch. 20 - Prob. 20.3QQCh. 20 - Characterize the paths in Figure 19.12 as...Ch. 20 - Prob. 20.5QQCh. 20 - An ideal gas is compressed to half its initial...Ch. 20 - A poker is a stiff, nonflammable rod used to push...Ch. 20 - Assume you are measuring the specific heat of a...Ch. 20 - Prob. 20.4OQCh. 20 - Prob. 20.5OQ
Ch. 20 - Ethyl alcohol has about one-half the specific heat...Ch. 20 - The specific heat of substance A is greater than...Ch. 20 - Beryllium has roughly one-half the specific heat...Ch. 20 - Prob. 20.9OQCh. 20 - A 100-g piece of copper, initially at 95.0C, is...Ch. 20 - Prob. 20.11OQCh. 20 - If a gas is compressed isothermally, which of the...Ch. 20 - Prob. 20.13OQCh. 20 - If a gas undergoes an isobaric process, which of...Ch. 20 - Prob. 20.15OQCh. 20 - Prob. 20.1CQCh. 20 - You need to pick up a very hot cooking pot in your...Ch. 20 - Prob. 20.3CQCh. 20 - Prob. 20.4CQCh. 20 - Prob. 20.5CQCh. 20 - In 1801, Humphry Davy rubbed together pieces of...Ch. 20 - Prob. 20.7CQCh. 20 - Prob. 20.8CQCh. 20 - Prob. 20.9CQCh. 20 - When camping in a canyon on a still night, a...Ch. 20 - Pioneers stored fruits and vegetables in...Ch. 20 - Prob. 20.12CQCh. 20 - Prob. 20.1PCh. 20 - Consider Joules apparatus described in Figure...Ch. 20 - Prob. 20.3PCh. 20 - The highest waterfall in the world is the Salto...Ch. 20 - What mass of water at 25.0C must be allowed to...Ch. 20 - The temperature of a silver bar rises by 10.0C...Ch. 20 - In cold climates, including the northern United...Ch. 20 - A 50.0-g sample of copper is at 25.0C. If 1 200 J...Ch. 20 - An aluminum cup of mass 200 g contains 800 g of...Ch. 20 - If water with a mass mk at temperature Tk is...Ch. 20 - A 1.50-kg iron horseshoe initially at 600C is...Ch. 20 - An electric drill with a steel drill bit of mass m...Ch. 20 - An aluminum calorimeter with a mass of 100 g...Ch. 20 - A 3.00-g copper coin at 25.0C drops 50.0 m to the...Ch. 20 - Two thermally insulated vessels are connected by a...Ch. 20 - A 50.0-g copper calorimeter contains 250 g of...Ch. 20 - Prob. 20.17PCh. 20 - How much energy is required to change a 40.0-g ice...Ch. 20 - A 75.0-g ice cube at 0C is placed in 825 g of...Ch. 20 - A 3.00-g lead bullet at 30.0C is fired at a speed...Ch. 20 - Steam at 100C is added to ice at 0C. (a) Find the...Ch. 20 - A 1.00-kg Mock of copper at 20.0C is dropped into...Ch. 20 - In an insulated vessel, 250 g of ice at 0C is...Ch. 20 - Prob. 20.24PCh. 20 - An ideal gas is enclosed in a cylinder with a...Ch. 20 - Prob. 20.26PCh. 20 - One mole of an ideal gas is warmed slowly so that...Ch. 20 - (a) Determine the work done on a gas that expands...Ch. 20 - An ideal gas is taken through a quasi-static...Ch. 20 - A gas is taken through the cyclic process...Ch. 20 - Consider the cyclic process depicted in Figure...Ch. 20 - Why is the following situation impossible? An...Ch. 20 - A thermodynamic system undergoes a process in...Ch. 20 - A sample of an ideal gas goes through the process...Ch. 20 - A 2.00-mol sample of helium gas initially at 300...Ch. 20 - (a) How much work is done on the steam when 1.00...Ch. 20 - Prob. 20.37PCh. 20 - One mole of an ideal gas does 3 000 J of work on...Ch. 20 - A 1.00-kg block of aluminum is warmed at...Ch. 20 - In Figure P19.22, the change in internal energy of...Ch. 20 - An ideal gas initially at Pi, Vi, and Ti is taken...Ch. 20 - An ideal gas initially at Pi, Vi, and Ti is taken...Ch. 20 - A glass windowpane in a home is 0.620 cm thick and...Ch. 20 - A concrete slab is 12.0 cm thick and has an area...Ch. 20 - A student is trying to decide what to wear. His...Ch. 20 - The surface of the Sun has a temperature of about...Ch. 20 - The tungsten filament of a certain 100-W lightbulb...Ch. 20 - At high noon, the Sun delivers 1 000 W to each...Ch. 20 - Two lightbulbs have cylindrical filaments much...Ch. 20 - Prob. 20.50PCh. 20 - A copper rod and an aluminum rod of equal diameter...Ch. 20 - A box with a total surface area of 1.20 m2 and a...Ch. 20 - (a) Calculate the R-value of a thermal window made...Ch. 20 - At our distance from the Sun, the intensity of...Ch. 20 - A bar of gold (Au) is in thermal contact with a...Ch. 20 - Prob. 20.56PCh. 20 - Prob. 20.57PCh. 20 - A gas expands from I to Fin Figure P20.58 (page...Ch. 20 - Gas in a container is at a pressure of 1.50 atm...Ch. 20 - Liquid nitrogen has a boiling point of 77.3 K and...Ch. 20 - An aluminum rod 0.500 m in length and with a cross...Ch. 20 - Prob. 20.62APCh. 20 - Prob. 20.63APCh. 20 - Prob. 20.64APCh. 20 - Prob. 20.65APCh. 20 - An ice-cube tray is filled with 75.0 g of water....Ch. 20 - On a cold winter day. you buy roasted chestnuts...Ch. 20 - Prob. 20.68APCh. 20 - An iron plate is held against an iron wheel so...Ch. 20 - Prob. 20.70APCh. 20 - A 40.0-g ice cube floats in 200 g of water in a...Ch. 20 - One mole of an ideal gas is contained in a...Ch. 20 - Review. A 670-kg meteoroid happens to be composed...Ch. 20 - Prob. 20.74APCh. 20 - Prob. 20.75APCh. 20 - Prob. 20.76APCh. 20 - Water in an electric teakettle is boiling. The...Ch. 20 - Prob. 20.78APCh. 20 - Prob. 20.79APCh. 20 - A student measures the following data in a...Ch. 20 - Consider the piston cylinder apparatus shown in...Ch. 20 - A spherical shell has inner radius 3.00 cm and...Ch. 20 - Prob. 20.83CPCh. 20 - (a) The inside of a hollow cylinder is maintained...
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- (a) What is the average metabolic rate in watts of a man who metabolizes 10,500 kJ of feed energy in one day? (b) What is the maximum amount of work in joules he can do without breaking down fat, assuming a maximum eficiency of 20.0%? (c) Compare his work output with the daily output of a 187W (0.250horsepower) motor.arrow_forward(a) How long will the energy in a 1470kJ (350kcal) cup of yogurt last in a woman doing work at the rate of 150 W with an efficiency of 20.0% (such as in leisurely climbing stairs)? (b) Does the time found in part (a) imply that it is easy to consume more food energy than you can reasonably expect to work off with exercise?arrow_forward(a) If you toss 10 coins, what percent of the time will you get the three most likely macrostates (6 heads and 4 tails, 5 heads and 5 tails, 4 heads and 6 tails)? (b) You can realistically toss 10 coins and count the number of heads and tails about twice a minute. At mat rate, how long will it take on average to get either 10 heads and 0 tails or 0 heads and 10 tails?arrow_forward
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