Concept explainers
(a)
The change in internal energy of the water in joules.
(a)
Answer to Problem 5SP
The change in internal energy of the water in joules is
Explanation of Solution
Given info: The amount of water in the beaker is
Work is done on the system, thus the work done will be negative.
Write the expression of first Law of
Here,
One calorie is equal to
Substitute
Conclusion:
The change in internal energy of the water in joules is
(b)
The change in the internal energy of the water in calories.
(b)
Answer to Problem 5SP
The change in the internal energy of the water in calories is
Explanation of Solution
Given info:
Write the expression of first Law of Thermodynamics
Here,
One calorie is equal to
Substitute
Conclusion:
The change in the internal energy of the water in calories is
(c)
The temperature change of the water.
(c)
Answer to Problem 5SP
Yes the answers in the above three sections are different when the work done is
Explanation of Solution
Given info:
Write the expression for temperature change in terms of specific heat capacity
Here,
Substitute
Conclusion:
The temperature change of the water is
(d)
To explain whether the answers in the first three parts will differ if the work done is
(d)
Answer to Problem 5SP
The temperature change of the water is
Explanation of Solution
Given info: The heat added to the system is
Write the expression of first Law of Thermodynamics
Here,
One calorie is equal to
Substitute
The change in internal energy in joules is
Write the expression for temperature change in terms of specific heat capacity
Here,
Substitute
All the three parts are giving different answers for
Conclusion:
Since internal energy and temperature change are depending on the values of heat added or removed and work done, the answer will be different for each values of heat added and work done.
Want to see more full solutions like this?
Chapter 10 Solutions
Physics of Everyday Phenomena
- (a) How much food energy will a man metabolize in the process of doing 35.0 kJ of work with an efficiency of 5.00%? (b) How much heal transfer occurs to the environment to keep his temperature constant? Explicitly show how you follow the steps in the Problem—Solving Strategy for thermodynamics found in Problem-Solving Strategies for Thermodynamics.arrow_forwardA power plant has been proposed that would make use of the temperature gradient in the ocean. The system is to operate between 20.0C (surface water temperature) and 5.00C (water temperature at a depth of about 1 km). (a) What is the maximum efficiency of such a system? (b) If the useful power output of the plant is 75.0 MW, how much energy is absorbed per hour? (c) In view of your answer to part (a), do you think such a system is worthwhile (considering that there is no charge for fuel)?arrow_forwardIn an air conditioner, 12.65 MJ of heat transfer occurs from a cold environment in 1.00 h. (a) What mass of ice melting would involve the same heat transfer? (b) How many hours of operation would be equivalent to mailing 900 kg of ice? (c) If ice costs 20 cents per kg, do you think the air conditioner could be operated more cheaply than by simply using ice? Describe in detail how you evaluate the relative costs.arrow_forward
- (a) Calculate the rate of heat transfer by radiation from a car radiator at 110C into a 50.0C environment, if the radiator has an emissivity of 0.750 and a 1.20m2 surface area. (b) Is this a significant fraction of the heat transfer by an automobile engine? To answer this, assume a horsepower of 200 hp (1.5 kW) and the efficiency of automobile engines as 25%.arrow_forwardA 4ton air conditioner removes 5.60107J (48,000 British thermal units) from a cold environment in 1.00 h. (a) What energy input in joules is necessary to do this if the air conditioner has an energy efficiency rating (EER) of 12.0? (b) What is the cost of doing this if the work costs 10.0 cents per 3.60106J (one kilowatt—hour)? (c) Discuss whether this cost seems realistic. Note that the energy efficiency rating (EER) of an air conditioner or refrigerator is defined to be the number of British thermal units of heat transfer from a cold environment per hour divided by the watts of power input.arrow_forward(a) How much heat transfer occurs to the environment by an electrical power station that uses 1.251014J of heat transfer into the engine with an efficiency of 42.0%? (b) What is the ratio of heat transfer to the environment to work output? (c) How much work is done?arrow_forward
- Unreasonable Results (a) What is the temperature increase of an 80.0 kg person who consumes 2500 kcal of food in one day with 95.0% of the energy transferred as heat to the body? (b) What is unreasonable about this result? (c) Which premise or assumption is responsible?arrow_forwardA person inhales and exhales 2.00 L of 37.0C air, evaporating 4.00102g of water from the lungs and breathing passages with each breath. (a) How much heat transfer occurs due to evaporation in each breath? (b) What is the rate of heat transfer in watts if the person is breathing at a moderate rate of 18.0 breaths per minute? (c) If the inhaled air had a temperature of 20.0C, what is the rate of heat transfer for warming the air? (d) Discuss the total rate of heat transfer as it relates to typical metabolic rates. Will this breathing be a major form of heat transfer for this person?arrow_forwardA bag containing 0C ice is much more effective in absorbing energy than one containing the same amount at 0C water. a. How much heat transfer is necessary to raise the temperature of 0.800 kg of water from 0C to 30.0C ? b. How much heat transfer is required to first melt 0.800 kg of 0C ice and then raise its temperature? c. Explain how your answer supports the contention that the ice is more effective.arrow_forward
- A power plant has been proposed that would make use of the temperature gradient in the ocean. The system is to operate between 20.0C (surface water temperature) and 5.00C (water temperature at a depth of about 1 km). (a) What is the maximum efficiency of such a system? (b) If the useful power output of the plant is 75.0 MW, how much energy is absorbed per hour? (c) In view of your answer to part (a), do you think such a system is worthwhile (considering that there is no charge for fuel)?arrow_forwardThe Sun radiates energy at the rate of 3.801026W from its 5500C surface into dark empty space (a negligible fraction radiates onto Earth and the other planets). The effective temperature of deep space is 270C. (a) What is the increase in entropy in one day due to this heat transfer? (b) How much work is made unavailable?arrow_forwardAssume you are measuring the specific heat of a sample of originally hot metal by using a calorimeter containing water. Because your calorimeter is not perfectly insulating, energy can transfer by heat between the contents of the calorimeter and the room. To obtain the most accurate result for the specific heat of the metal, you should use water with which initial temperature? (a) slightly lower than room temperature (b) the same as room temperature (c) slightly higher than room temperature (d) whatever you like because the initial temperature makes no differencearrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning