Physics Laboratory Manual
4th Edition
ISBN: 9781133950639
Author: David Loyd
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 39, Problem 2PLA
What is the constant ratio between electrical energy (in joules) when it is converted completely to heat (in calories)? This is commonly referred to as the mechanical equivalent of heat (MEH).
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Many decisions are made on the basis of the payback period: the time it will take through savings to equal the capital cost of an investment. Acceptable payback times depend upon the business or philosophy one has. (For some industries, a payback period is as small as two years.) Suppose you wish to install the extra insulation. If energy cost $1.00 per million joules and the insulation was $4.00 per square meter, then calculate the simple payback time. Take the average for the 120 day heating season to be 15.0C.
Many decisions are made on the basis of the payback period: the time it will take through savings to equal the capital cost of an investment. Acceptable payback times depend upon the business or philosophy one has. (For some industries, a payback period is as small as two years.) Suppose you wish to install the extra insulation in Exercise. If energy cost $1.00 per million joules and the insulation was $4.00 per square meter, then calculate the simple payback time. Take the average ΔT for the 120 day heating season to be 15.0ºC.
Consider the thermodynamic process, A->B->C->A shown above. The heat absorbed during A->B is 591J. If the change in internal energy during B->C is 4146J, What is the change in internal energy in SI units during C->A? Express only the number of your answer with 4 significant figures.
Chapter 39 Solutions
Physics Laboratory Manual
Ch. 39 - Prob. 1PLACh. 39 - What is the constant ratio between electrical...Ch. 39 - A resistor has a current of 3.75 A when its...Ch. 39 - A resistor has a resistance of 1.50 and a voltage...Ch. 39 - If the resistor in Question 4 is immersed in...Ch. 39 - A resistor has a voltage of 6.65 V and a current...
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
- An electric hot plate raises its own internal energy and the internal energy of a cup of water by 15000 J, and there is at the same time 2900 J transferred to the cooler air (that is, Q = -2900 J). How much energy was transferred to the hot plate in the form of electricity? electric energy input = iarrow_forwardA PHYS 1510 student was working on a robotics project. The joints on the machine they were building were powered by pistons. Based on how hot the machine was getting, the student was able to figure out that 2.34 J of thermal energy was produced by every piston every time the piston was fully extended to 0.4064 m. What was the force of friction that the piston experienced during every extension? Assume friction is the only source of thermal energy. Include units in Sl.arrow_forwardHow much energy would you consume daily if you kept 3 lightbulbs of 25 watts on all day long?.arrow_forward
- A Carnot air conditioner takes energy from the thermal energy of a room at 70 F and transfers it as heat to the outdoors, which is at 96 F.For each joule of electric energy required to operate the air conditioner, how many joules are removed from the room?arrow_forwardA typical coal-fired power plant burns 340 metric tons of coal every hour to generate 2.5 × 106 MJ of energy. One metric ton has a mass of 1000 kg and a metric ton of coal has a volume of 1.5 m^3. The heat of combustion is 28 MJ/kg. What is the power plant’s efficiency?arrow_forwardWhy do we not use brakes with more than 80% efficiency in automobiles? Whatshould be the minimum stopping distance for a car running at 80 kph?arrow_forward
- The metabolic power for typing is 150 W for Lili, not a lot as you know probably. How long does it take to burn off the energy in a slice of apple pie, which energy content is 1680 kJ (400 food calorie), in minutes? (Try to stay active, working/studying in front of a computer is not the best exercise you can do for your body.) Your answer needs to have 3 significant figures, including the negative sign in your answer if needed. Do not include the positive sign if the answer is positive. No unit is needed in your answer, it is already given in the question statement.arrow_forward8.8 J of work expands an ideal gas in a metal piston cylinder in a bucket of ice water from 3.7 cubic centimeters to 9.9 cubic centimeters. How much heat was transferred from the ice water to the gas? If you feel this question is incomplete, please explain HOW it is incomplete.arrow_forward250 students sit in an auditorium listening to a physics lecture. Because they are thinking hard, each is using 125 W of metabolic power, slightly more than they would use at rest. An air conditioner with a COP of 5.0 is being used to keep the room at a constant temperature. What minimum electric powermust be used to operate the air conditioner?arrow_forward
- You use a quantity of fuel with a total energy content of 19.02 MJ to power an engine. If the average output of the engine over 2 hours was 2.12 kW, what is the efficiency of the engine?arrow_forwardA heat engine has a solar collector receiving 600 Btu/h per square foot, inside which a transfer medium is heated to 800 R. The collected energy powers a heat engine that rejects heat at 100 F. If the heat engine should deliver 8500 Btu/h, what is the minimum size (area) of the solar collector?arrow_forwardLet us use a heat pump to cook dinner! You set up a heat pump that has 40 % of its theoretical maximum COP, and you want to use heat from the kitchen at 24°C to supply 600 W of heat energy for boiling soup. Assume the soup is mostly water and that you want to heat it to 100°C. (a) How much electrical energy must the heat pump use? The heat pump uses _______J of electrical energy. (b) How much better is this than simply using an electric hot plate to supply the 600 W of heat energy? Using a heat pump is _____ times better than using an electric hot plate.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
The Second Law of Thermodynamics: Heat Flow, Entropy, and Microstates; Author: Professor Dave Explains;https://www.youtube.com/watch?v=MrwW4w2nAMc;License: Standard YouTube License, CC-BY