College Physics (10th Edition)
10th Edition
ISBN: 9780321902788
Author: Hugh D. Young, Philip W. Adams, Raymond Joseph Chastain
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
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?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A person is standing outdoors in the shade where the temperature is 21 °C. (a) What is the radiant energy absorbed per second by his head when it is covered with hair? The surface area of the hair (assumed to be flat) is 190 cm2 and its emissivity is 0.84. (b) What would be the radiant energy absorbed per second by the same person if he were bald and the emissivity of his head were 0.56?
What is the rate of heat transfer by radiation, with an unclothed person standing in a dark room whose ambient temperature is 22.0ºC . The person has a normal skin temperature of 33.0ºC and a surface area of 1.50 m2 . The emissivity of skin is 0.97 in the infrared, where the radiation takes place.
A common practice for a person with a high fever is to take a bath in cool water. Assuming an 80 kg person is really ill and needs to cool down from 40°C to 37°C. What is the minimum amount of water needed for bathing assuming the water begins at room temperature, 25°C? The specific heat of the body on average is 3470 J/kg°C and water is 4186 J/kg°C.
16.6 kg
212.2 kg
200 kg
19.8 kg
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...
Additional Science Textbook Solutions
Find more solutions based on key concepts
The missing entries of the table.
Physics (5th Edition)
10. Why is it important to study physics? Provide a few examples of what an understanding of the physical world...
Applied Physics (11th Edition)
(a) Show that .
[Hint: Use integration by parts.]
(b) Let be the step function: . (1.95)
Show that .
Introduction to Electrodynamics
8. A 1000 kg car pushes a 2000 kg truck that has a dead battery. When the driver steps on the accelerator, the ...
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
If all the molecules of a body remained part of that body, would the body have any odor?
Conceptual Integrated Science
Recall the motion of the block in part B. For each force that you identified, state whether that force did posi...
Tutorials in Introductory Physics
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
- Beryllium has roughly one-half the specific heat of water (H2O). Rank the quantities of energy input required to produce the following changes from the largest to the smallest. In your ranking, note any cases of equality, (a) raising the temperature of 1 kg of H2O from 20C to 26C (b) raising the temperature of 2 kg of H2O from 20C to 23C (c) raising the temperature of 2 kg of H2O from 1C to 4C (d) raising the temperature of 2 kg of beryllium from 1C to 2C (e) raising the temperature of 2 kg of H2O from -1C to 2Carrow_forward(a) What is the rate of heat conduction through the 3.00-cm-thick fur of a large animal having a I .40-m surface area? Assume that the animal's skin temperature is 32.0 , that the air temperature is 5.00 , and that has the same thermal conductivity as air. (b) What food intake will the animal need in one day to replace this heat transfer?arrow_forwardDuring heavy exercise, the body pumps 2.00 L of blood per minute to the surface, where it is cooled by 2.00C. What is the rate of heat transfer from this forced convection alone, assuming blood has the same specific heat as water and its density is 1050kg/m3 ?arrow_forward
- What is the rate of heat conduction through the 3.61-cm-thick fur of a large animal having a 1.29~\text{m}^21.29 m2 surface area? Assume that the animal’s skin temperature is 32.0^\circ\text{C}32.0∘C, that the air temperature is -5.00^\circ\text{C}−5.00∘C, and that fur has the same thermal conductivity as air. Select the correct answer 58.4 W 23.2 W 41.3 W 30.4 W 74.0 Warrow_forwardA silver kettle weighs 1.07 kg. (The specific heat of silver is 0.235 J/g·°C) (a) What is the heat capacity (in J/°C) of the kettle? _____ J/°C (b) How much heat (in J) is required to increase the temperature of this kettle from 20.5°C to 98.7°C? _____ J (c) How much heat (in J) is required to heat this kettle from 20.5°C to 98.7°C if it contains 1.03 L of water (density of 0.997 g/mL and a specific heat of 4.18 J/g·°C across the temperature range)? _____ Jarrow_forwardA 0.250-kg aluminum bowl holding 0.800 kg of soup at 25.0°C is placed in a freezer. What is the final temperature if 430 kJ of energy is transferred from the bowl and soup? Assume the soup has the same thermal properties as that of water, the specific heat of the liquid soup is 1.00 kcal/(kg · °C), frozen soup is 0.500 kcal/(kg · °C), and the latent heat of fusion is 79.8 kcal/kg. The specific heat of aluminum is 0.215 kcal/(kg · °C).arrow_forward
- An inventor develops a stationary cycling device by which an individual, while pedaling, can convert all of the energy expended into heat for warming water. How much mechanical energy is required to increase the temperature of 300 g of water (enough for one cup of coffee) from 20 deg C to 95 deg C? (Water has a specific heat of 4186 J/kg deg C.) A mediocre cyclist can produce 131 J of energy per second. How long (in minutes) would it take this cyclist to heat the cup of water in the previous problem for hot chocolate?arrow_forwardThe quantity of heat Q that changes the temperature ∆T of a mass m of a substance is given by Q = cm∆Tc is the specific heat capacity of the substance. For example, for H2O, c = 1 cal/g°C. And for a change of phase, the quantity of heat Q that changes the phase of a mass m is Q = mL, where L is the heat of fusion or heat of vaporization of the substance. For example, for H2O, the heat of fusion is 80 cal/g (or 80 kcal/kg) and the heat of vaporization is 540 cal/g (or 540 kcal/kg). Use these relationships to determine the number of calories to change (a) 1 kg of 0°C ice to 0°C ice water, (b) 1 kg of 0°C ice water to 1 kg of 100°C boiling water, (c) 1 kg of 100°C boiling water to 1 kg of 100°C steam, and (d) 1 kg of 0°C ice to 1 kg of 100°C steam.arrow_forwardThe basal metabolic rate is the rate at which energy is produced in the body when a person is at rest. A 75 kgkg (165 lblb) person of height 1.85 mm (6.07 ftft) would have a body surface area of approximately 2.00 m2m2. Part A What is the net amount of heat this person could radiate per second into a room at 17.0 ∘C∘C (about 62.6 ∘F∘F) if his skin's surface temperature is 31.0 ∘C∘C? (At such temperatures, nearly all the heat is infrared radiation, for which the body's emissivity is 1.0, regardless of the amount of pigment.) Express your answer with the appropriate units. HnetHnet = nothingnothing SubmitRequest Answer Part B Normally, 80%% of the energy produced by metabolism goes into heat, while the rest goes into things like pumping blood and repairing cells. Also normally, a person at rest can get rid of this excess heat just through radiation. Use your answer to part A to find this person's basal metabolic rate…arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College
Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Physics for Scientists and Engineers, Technology ...
Physics
ISBN:9781305116399
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
Physics for Scientists and Engineers with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Heat Transfer: Crash Course Engineering #14; Author: CrashCourse;https://www.youtube.com/watch?v=YK7G6l_K6sA;License: Standard YouTube License, CC-BY