![Pearson eText for College Physics: Explore and Apply -- Instant Access (Pearson+)](https://www.bartleby.com/isbn_cover_images/9780137443000/9780137443000_largeCoverImage.gif)
* BIO Exercising warms body A 50-kg woman repeatedly lifts a 20-kg barbell 0.80 m from her chest to an extended position above her head. (a) If her body retains 10 J of thermal energy for each joule of work done while lifting, how many times must she lift the barbell to warm her body
![Check Mark](/static/check-mark.png)
Want to see the full answer?
Check out a sample textbook solution![Blurred answer](/static/blurred-answer.jpg)
Chapter 15 Solutions
Pearson eText for College Physics: Explore and Apply -- Instant Access (Pearson+)
Additional Science Textbook Solutions
Lecture- Tutorials for Introductory Astronomy
College Physics (10th Edition)
The Cosmic Perspective (8th Edition)
Sears And Zemansky's University Physics With Modern Physics
Tutorials in Introductory Physics
Conceptual Physics (12th Edition)
- For each of the following systems and time intervals, write the appropriate version of Equation 8.2, the conservation of energy equation. (a) the heating coils in your toaster during the first five seconds after you turn the toaster on (b) your automobile from just before you fill it with gasoline until you pull away from the gas station at speed (c) your body while you sit quietly and eat a peanut butter and jelly sandwich for lunch (d) your home during live minutes of a sunny afternoon while the temperature in the home remains fixedarrow_forwardIn a running event, a sprinter does 4.8 105 J of work and her internal energy decreases by 7.5 105 J. (a) Determine the heat transferred between her body and surroundings during this event. (b) What does the sign of your answer to part (a) indicate?arrow_forwardIn 1990 Walter Arfeuille of Belgium lifted a 281.5-kg object through a distance of 17.1 cm using only his teeth. (a) How much work did Arfeuille do on the object? (b) What magnitude force did he exert on the object during the lift, assuming the force was constant?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_forwardShoveling snow can be extremely taxing because the arms have such a low efficiency in this activity. Suppose a person shoveling a footpath metabolizes food at the rate of 800 W. (a) What is her useful power output? (b) How long will it take her to lift 3000 kg of snow 1.20 m? (This could be the amount of heavy snow on 20 m of footpath.) (c) How much waste heat transfer in kilojoules will she generate in the process?arrow_forward(a) The number of kilocalories in food is determined by calorimetry techniques in which the food is burned and the amount at heat transfer is measured. How many kilocalories per gram are there in a 5.00g peanut if the energy from burning it is transferred to 0.500 kg of water held in a 0.100kg aluminum cup, causing a 54.9C temperature increase? (b) Compare your answer to labeling information found on a package of peanuts and comment on whether the values are consistent.arrow_forward
- A 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_forwardA 75-kg sprinter accelerates from rest to a speed of 11.0 m/s in 5.0 s. (a) Calculate the mechanical work done by the sprinter during this time. (b) Calculate the average power the sprinter must generate. (c) If the sprinter converts food energy to mechanical energy with an efficiency of 25%, at what average rate is he burning Calories? (d) What happens to the other 75% of the food energy being used?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
- What is the net work output of a heat engine that follows path ABBA in the figure above, with a straight line from B to D? Why is the work output less than for path ABCDA? Explicitly show how you follow the steps in the Problem Solving Strategies for Thermodynamics.arrow_forward(a) Prepare a table like Table 21.1 for the following occurrence. You toss four coins into the air simultaneously and then record the results of your tosses in terms of the numbers of heads (H) and tails (T) that result. For example, HHTH and HTHH are two possible ways in which three heads and one tail can be achieved. (b) On the basis of your table, what is the most probable result recorded for a toss?arrow_forwardUnreasonable Results (a) Suppose you want to design a steam engine that has heat transfer to the environment at 270C and has a Carnot eficiency of 0.800. What temperature of hot Steam must you use? (b) What is unreasonable about the temperature? (c) Which premise is unreasonable?arrow_forward
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegePrinciples 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
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
![Text book image](https://www.bartleby.com/isbn_cover_images/9781938168000/9781938168000_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781133104261/9781133104261_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781337553292/9781337553292_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305116399/9781305116399_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305952300/9781305952300_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781285737027/9781285737027_smallCoverImage.gif)