Suppose a woman does 663 J of work and dissipates 7,454 J of
heat in the process.
Suppose a woman does 663 J of work and dissipates 7,454 J of heat in the...
2) Suppose a woman does 550 J of work and dissipates 9800 J of heat in the process. (a) What is the decrease in her internal energy, assuming no change in temperature or consumption of food? (That is, there is no other energy transfer.) Express your answer in kcal. kcal (b) What is her efficiency? % 3) (a) How long will the energy in a 310 kcal cup of yogurt last in a woman doing work at the rate of...
Suppose a woman does 463 J of work and dissipates 8,854 J of heat in the process. (a) What is the decrease in her internal energy, assuming no change in temperature or consumption of food? (That is, there is no other energy transfer.) kcal (b) What is her efficiency? %
(a) How long in minutes will the energy in a 963 kJ (230 kcal) cup of yogurt last in a woman doing work at the rate of 130 W with an efficiency of 20.0% (such as in leisurely climbing stairs)? _______min (b) Does the time found in part (a) imply that it is easy to consume more food energy than you can reasonably expect to work off with exercise? Yes/No
A 52-kg woman eats a 640 Calorie (640 kcal) jelly doughnut for breakfast. (a) How many joules of energy are the equivalent of one jelly doughnut? _________ J (b) How many steps must the woman climb on a very tall stairway to change the gravitational potential energy of the woman-Earth system by a value equivalent to the food energy in one jelly doughnut? Assume the height of a single stair is 15 cm. _________ stairs (c) If the human body...
(a) What is the efficiency of an out-of-condition professor who does 2.00 ? 105 J of useful work while metabolizing 510 kcal of food energy? _______% (b) How many food calories would a well-conditioned athlete metabolize in doing the same work with an efficiency of 15%? _______kcal
Suppose the work done to compress a gas is 100 J. If 70 J of heat is lost in the process, what is the change in the internal energy of the gas? Hint: Use the first law of thermodynamics. The internal energy of a system changes due to heat (Q) and work (W): U=Q-W. The change in internal energy is equivalent to the difference between the heat added to the system and the work done by the system. Think if...
A system does 5.0 × 104 J of work, and 8.7 × 104 J of heat flows into the system during the process. Find the change in the internal energy of the system. ΔU =
During a process a system releases 12.4 J of heat and does 4.2 J of work on the surroundings. The change in internal energy (ΔU) of the system is _____ J. and the answer is not -8.2
A system does 181 J of work on its environment and gains 98.3 J of heat in the process. Find the change in the internal energy of (a) the system and (b) the environment.
A heat engine does 4270 J of work with an efficiency of 0.800. How much energy is dumped to the cold reservoir of this engine?