Chapter 7: Q7.1-2 PE (page 260)
A \(75.0 - {\rm{kg}}\) person climbs stairs, gaining \(2.50{\rm{ meters}}\) in height. Find the work done to accomplish this task.
Short Answer
The work done is \(1837.5{\rm{ J}}\).
Chapter 7: Q7.1-2 PE (page 260)
A \(75.0 - {\rm{kg}}\) person climbs stairs, gaining \(2.50{\rm{ meters}}\) in height. Find the work done to accomplish this task.
The work done is \(1837.5{\rm{ J}}\).
All the tools & learning materials you need for study success - in one app.
Get started for freeBody fat is metabolized, supplying 9.30 kcal/g, when dietary intake is less than needed to fuel metabolism. The manufacturers of an exercise bicycle claim that you can lose 0.500 kg of fat per day by vigorously exercising for 2.00 h per day on their machine.
(a) How many kcal are supplied by the metabolization of 0.500 kg of fat?
(b) Calculate the kcal/ min that you would have to utilize to metabolize fat at the rate of 0.500 kg in 2.00 h.
(c) What is unreasonable about the results?
(d) Which premise is unreasonable, or which premises are inconsistent?
Question: (a) Calculate the energy in kJ used by a 55.0-kg woman who does 50 deep knee bends in which her center of mass is lowered and raised 0.400 m. (She does work in both directions.) You may assume her efficiency is 20%.
(b) What is the average power consumption rate in watts if she does this in 3.00 min?
What is the difference between energy conservation and the law of conservation of energy? Give some examples of each.
A subway train is brought to a stop from a speed ofinby a large spring bumper at the end of its track. What is the force constant k of the spring?
(a) What is the efficiency of an out-of-condition professor who does \(2.10 \times {10^5}{\rm{ J}}\) of useful work while metabolizing \(500{\rm{ kcal}}\) of food energy?
(b) How many food calories would a well-conditioned athlete metabolize in doing the same work with an efficiency of \(20\% \)?
What do you think about this solution?
We value your feedback to improve our textbook solutions.