Fred has the idea to improve the efficiency of a certain heat engine exploiting a high-temperature reservoir, by using part of its output to run a refrigerator which cools a low-temperature (finite-sized) heat sink to a temperature below the environmental temperature. fiona tells fred that his efforts are futile. who is correct? in particular, what can you say about the overall efficiency of fred's scheme, assuming everything operates reversibly?

Mass (kg) force (n) 5 25 10 50 15 75 20 100 a student was trying to find the relationship between mass and force. he placed four different masses on a table and pulled them using a spring scale. the table shows the different masses used in the experiment and the force required to pull each mass. the student concluded that more force was required to pull heavier objects. what comment would you make regarding his conclusion? a) no clear relation can be observed between mass and force from the data. b) there is a direct proportion between the mass and force listed in the table. c) gravity should have been taken into account while performing the experiment. d) there is an inverse proportion between the mass and force listed in the table.

The volume of a gas is halved during an adiabatic compression that increases the pressure by a factor of 2.5. what is the specific heat ratio? show the math steps .

Apair of 10μf capacitors in a high-power laser are charged to 1.7 kv.a. what charge is stored in each capacitor? b. how much energy is stored in each capacitor?