College Physics
11th Edition
ISBN: 9781305952300
Author: Raymond A. Serway, Chris Vuille
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 11, Problem 70AP
(a)
To determine
The mass of waxy material required to conduct the bacteriological test.
(b)
To determine
Why the calculation can be done without knowing the mass of the test samples or of the insulation.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
For bacteriological testing of water supplies and in medical clinics, samples must routinely be incubated for 24 h at 37°C. A standard constant - temperature bath with electric heating and thermostatic control is not suitable in developing nations without continuously operating electric power lines. Peace Corps volunteer and MIT engineer Amy Smith invented a low - cost, low-maintenance incubator to fill the need. The device consists of a foam-insulated box containing several packets of a waxy material that melts at 37.0°C, interspersed among tubes, dishes, or bottles containing the test samples and growth medium (food for bacteria). Outside the box, the waxy material is first melted by a stove or solar energy collector. Then it is put into the box to keep the test samples warm as it solidifies. The heat of fusion of the phase-change material is 205 kJ/kg. Model the insulation as a panel with surface area 0.490 m2, thickness 9.50 cm, and conductivity 0.012 0 W/m ∙ °C. Assume the…
A certain car has 14 L of liquid coolant circulating at a temperature of 95 degrees Celsius through the engine’s cooling system. Assume that, in this normal condition, the coolant completely fills the 3.5 L volume of the aluminum radiator and the 10.5 L internal cavities within the aluminum engine. When a car overheats, the radiator, engine, and coolant expand and a small reservoir connected to the radiator catches any resultant coolant overflow. Estimate how much coolant overflows to the reservoir if the system goes from 95 degrees Celsius to 106 degrees Celsius. Model the radiator and engine as hollow shells of aluminum. The coefficient of volume expansion for coolant is 410x10^-6 degrees Celsius
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…
Chapter 11 Solutions
College Physics
Ch. 11.2 - Prob. 11.1QQCh. 11.4 - Prob. 11.2QQCh. 11.5 - Will an ice cube wrapped in a wool blanket remain...Ch. 11.5 - Two rods of the same length and diameter are made...Ch. 11.5 - Stars A and B have the same temperature, but star...Ch. 11 - Rub the palm of your hand on a metal surface for...Ch. 11 - On a clear, cold night, why does frost tend to...Ch. 11 - Substance A has twice the specific heat of...Ch. 11 - Equal masses of substance A at 10.0C and substance...Ch. 11 - Prob. 5CQ
Ch. 11 - Prob. 6CQCh. 11 - Cups of water for coffee or tea can be warmed with...Ch. 11 - The U.S. penny is now made of copper-coated zinc....Ch. 11 - A tile floor may feel uncomfortably cold to your...Ch. 11 - In a calorimetry experiment, three samples A, B,...Ch. 11 - Figure CQ11.11 shows a composite bar made of three...Ch. 11 - Objects A and B have the same size and shape with...Ch. 11 - A poker is a stiff, nonflammable rod used to push...Ch. 11 - On a very hot day, its possible to cook an egg on...Ch. 11 - Prob. 15CQCh. 11 - Star A has twice the radius and twice the absolute...Ch. 11 - Convert 3.50 103 cal to the equivalent number of...Ch. 11 - Prob. 2PCh. 11 - A 75-kg sprinter accelerates from rest to a speed...Ch. 11 - Prob. 4PCh. 11 - A persons basal metabolic rate (BMR) is the rate...Ch. 11 - The temperature of a silver bar rises by 10.0C...Ch. 11 - The highest recorded waterfall in the world is...Ch. 11 - An aluminum rod is 20.0 cm long at 20.0C and has a...Ch. 11 - Lake Erie contains roughly 4.00 1011 m3 of water....Ch. 11 - A 3.00-g copper coin at 25.0C drops 50.0 m to the...Ch. 11 - Prob. 11PCh. 11 - Prob. 12PCh. 11 - Prob. 13PCh. 11 - A 1.5-kg copper block is given an initial speed of...Ch. 11 - Prob. 15PCh. 11 - Prob. 16PCh. 11 - What mass of water at 25.0C must be allowed to...Ch. 11 - Lead pellets, each of mass 1.00 g, are heated to...Ch. 11 - Prob. 19PCh. 11 - A large room in a house holds 975 kg of dry air at...Ch. 11 - Prob. 21PCh. 11 - A 1.50-kg iron horseshoe initially at 600C is...Ch. 11 - A student drops two metallic objects into a 120-g...Ch. 11 - When a driver brakes an automobile, the friction...Ch. 11 - A Styrofoam cup holds 0.275 kg of water at 25.0C....Ch. 11 - Prob. 26PCh. 11 - Prob. 27PCh. 11 - How much thermal energy is required to boil 2.00...Ch. 11 - A 75-g ice cube al 0C is placed in 825 g of water...Ch. 11 - Prob. 30PCh. 11 - Prob. 31PCh. 11 - Prob. 32PCh. 11 - Prob. 33PCh. 11 - Prob. 34PCh. 11 - Prob. 35PCh. 11 - Prob. 36PCh. 11 - A high-end gas stove usually has at least one...Ch. 11 - Prob. 38PCh. 11 - Steam at 100.C is added to ice at 0C. (a) Find the...Ch. 11 - The excess internal energy of metabolism is...Ch. 11 - A 3.00-g lead bullet at 30.0C is fired at a speed...Ch. 11 - A glass windowpane in a home is 0.62 cm thick and...Ch. 11 - A pond with a flat bottom has a surface area of...Ch. 11 - The thermal conductivities of human tissues vary...Ch. 11 - A steam pipe is covered with 1.50-cm-thick...Ch. 11 - The average thermal conductivity of the walls...Ch. 11 - Consider two cooking pots of the same dimensions,...Ch. 11 - A thermopane window consists of two glass panes,...Ch. 11 - A copper rod and an aluminum rod of equal diameter...Ch. 11 - A Styrofoam box has a surface area of 0.80 m and a...Ch. 11 - A rectangular glass window pane on a house has a...Ch. 11 - A granite ball of radius 2.00 m and emissivity...Ch. 11 - Measurements on two stars indicate that Star X has...Ch. 11 - The filament of a 75-W light bulb is at a...Ch. 11 - The bottom of a copper kettle has a 10.0-cm radius...Ch. 11 - A family comes home from a long vacation with...Ch. 11 - A 0.040.-kg ice cube floats in 0.200 kg of water...Ch. 11 - The surface area of an unclothed person is 1.50...Ch. 11 - A student measures the following data in a...Ch. 11 - Prob. 60APCh. 11 - A class of 10 students; taking an exam has a power...Ch. 11 - A class of 10 students taking an exam has a power...Ch. 11 - A bar of gold (Au) is in thermal contact with a...Ch. 11 - An iron plate is held against an iron, wheel so...Ch. 11 - Prob. 65APCh. 11 - Three liquids are at temperatures of 10C, 20C, and...Ch. 11 - Earths surface absorbs an average of about 960....Ch. 11 - A wood stove is used to heat a single room. The...Ch. 11 - Prob. 69APCh. 11 - Prob. 70APCh. 11 - The surface of the Sun has a temperature of about...Ch. 11 - The evaporation of perspiration is the primary...Ch. 11 - Prob. 73APCh. 11 - An ice-cube tray is filled with 75.0 g of water....Ch. 11 - An aluminum rod and an iron rod are joined end to...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- A solar hot-water-heating system consists of a hot-water tank and a solar panel. The tank is well insulated and has a time constant of 60 hr. The solar panel generates 2200 Btu/hr during the day, and the tank has a heat capacity of 3°F per thousand Btu. If the water in the tank is initially 105°F and the room temperature outside the tank is 81°F, what will be the temperature in the tank after 10 hr of sunlight? What is U(t), the rate of temperature change due to the solar heating panel? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. U(t)= °F/hr OB. U(t) is unknown. xample Get more help Clear all Check answerarrow_forwardIf mercury overflows, it’ll trigger an alarm in the lab. The teacher wants to keep the lab at exactly 16.37 ◦C. While the mercury alarm is in place. How long would a person of average body size (surface area of about 1.8 m2 and normal body temperature of 37◦C) have to spend in the lab which holds 2700 moles of air to trigger the mercury alarm? Side note: The maximum temperature the lab can heat the system to (to the thousandth of a degree Celsius) before the mercury overflows is 16.37◦C. Please show all work with equations that are used.arrow_forwardA person infected with the SARS-CoV-2 virus is running a fever with an internal body temperature of 103 °F (39.4 °C). This raises the person's skin temperature to 36.5 °C. The person is standing unclothed in a room with an ambient temperature of 21.0 °C. If the temperature of the person's skin is maintained at 36.5 °C solely by the energy obtained from the metabolic conversion of food, how many Calories would this person have to consume per hour? Assume heat is lost only by radiation, and the surface area and emissivity of the person's skin are 1.50 m² and 0.800, respectively. Number Unitsarrow_forward
- Two evacuated bulbs are connected by a tube of negligible volume. The volume of one of the bulbs is twice that of the other. The larger volume bulb is placed in a 200K Isother constant-temperature bath and the other in a 300K bath, and then 1.00mol of an ideal me gas is injected into the system. Find the final number of moles of gas in each bulb.arrow_forwardTotal lung capacity of a typical adult is approximately 5.0 L. Approximately 20% of the air is oxygen. At sea level and at an average body temperature of 37°C, how many moles of oxygen do the lungs contain at the end of an inhalation?arrow_forwardAn airtight container with the piston at 696(kPa) pressure and 269(K) temperature. When 105 kJ heat is transferred, the piston moves up and the volume changes from 0.014 to 0.056 m°. Assuming ideal gas behavior, calculate a) the change in internal energy, b) the final temperature, and c) the heat capacity.arrow_forward
- A high-pressure gas cylinder contains 80.0 L of toxic gas at a pressure of 1.20 107 N/m2 and a temperature of 12.0°C. Its valve leaks after the cylinder is dropped. The cylinder is cooled to dry ice temperatures (−78.5°C), to reduce the leak rate and pressure so that it can be safely repaired. what is the final pressure in the tank, assuming a negligible amount of gas leaks while being cooled and that there is no phase change? What is the final pressure if one-tenth of the gas escapes? To what temperature must the tank be cooled to reduce the pressure to 1.00 atm (assuming the gas does not change phase and that there is no leakage during cooling)?arrow_forwardA test is conducted to determine the overall heat transfer coefficient in a shell-and-tube oil-to-water heat exchanger that has 24 tubes of internal diameter 1.2 cm and length 2 m in a single shell. Cold water (cp = 4180 J/kg·K) enters the tubes at 20°C at a rate of 3 kg/s and leaves at 55°C. Oil (cp = 2150 J/kg·K) flows through the shell and is cooled from 120°C to 45°C. Determine the overall heat transfer coefficient Ui of this heat exchanger based on the inner surface area of the tubes.arrow_forwardYou are studying the strength of transparent aluminum tanks to bring some blue whales from past earth to future earth with Scotty. A diaphragm pump generates negative pressure in a chamber; air is pulled out of the chamber creating an atmosphere at very low pressure. If the chamber was originally at 0.80 atm with 28.00 moles of carbon dioxide in the chamber, how many moles remain if the final pressure is 0.027atm? Assume constant temperature and volumearrow_forward
- You wish to buy a new freezer for your basement. The primary use of the freezer will be to prepare ice for family parties. You have a very large family, with grandparents, parents, sisters, brothers, uncles, aunts, cousins, nephews, nieces, and grandchildren. As a result, family birthday parties are held every couple of weeks, and you need lots of ice for drinks. You want the freezer to convert 10.5 kg of water at 23.5°C to 10.5 kg of ice at -8.6°C in 2.00 h. But, in order to keep your electric bill down, you want the power rating of the freezer to stay below 100 W. From these requirements, you determine the minimum COP of the freezer that will satisfy your needs. (Consider that the specific heat of water is 4,186 J/(kg. °C), the specific heat of ice is 2,090 J/(kg. °C), the latent heat of fusion of water is 3.33 x 105 J/kg, and the latent heat of vaporization of water is 2.26 x 106 J/kg.) COP = Need Help? Read Itarrow_forwardA patient has suffered blood loss and a health care provider is preparing a saline solution for injection. The osmotic pressure of red blood cell is 7 atm, and the prepared solution should be isotonic with those cells. Note: body temperature is 37.15°C and that the gas constant R is 8.206×10 -2 L'atm K-mol The conversion of temperature from °C to Kelvin is T in K = T°C+273.15 (a) To prepare the saline solution, how many moles n of solute should be put into 2 L of distilled water? n = mol (b) Mistakenly, the concentration of the solution is only 1/4 of what it should be. What would be the net osmotic pressure exerted on the walls of the red blood cells? Hint: The concentrations inside the cell and outside the cell are now different. How can you calculate the net osmotic pressure? net = (c) The solution from part B is: atm (d) The diameter of a typical red blood cell is 5.98 μm. Calculate the net force the solution experiences across the cell membrane. Hint: We can assume that the red…arrow_forwardThe heat capacity of air at room temperature and pressure is approximately 21 J×mol-1×K-1. a) How much energy is required to raise the temperature of a room dimensions 5.5 m x 6.5 m x 3.0 m by 10°C from room temperature (298.15 K) assuming ideal behavior? b) How long will it take a heater rated at 1.5 kW to achieve that increase if 1 W = 1 J×s-1 (assuming no loss)?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
University Physics (14th Edition)
Physics
ISBN:9780133969290
Author:Hugh D. Young, Roger A. Freedman
Publisher:PEARSON
Introduction To Quantum Mechanics
Physics
ISBN:9781107189638
Author:Griffiths, David J., Schroeter, Darrell F.
Publisher:Cambridge University Press
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:9780321820464
Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:Addison-Wesley
College Physics: A Strategic Approach (4th Editio...
Physics
ISBN:9780134609034
Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:PEARSON