1. [-/1 Points] DETAILS OSCOLPHY52016 15.1.P.001. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER What is the change in internal energy (in J) of a car if you put 11.9 gal of gasoline into its tank? The energy content of gasoline is 1.3 x 105 J/gal. All other factors, such as the car's temperature, are constant. Addiiional Materials in Reading 2. [-/1 Points] DETAILS OSCOLPHYSZO16 15.1.P.003. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A system does 1.90 x 108 J of work while 8.20 x 108 J of heat transfer occurs to the environment. What is the change in internal energy (in J) of the system assuming no other changes (such as in temperature or by the addition of fuel)? (Include the sign of the value in your answer.) J 3. [-/1 Points] DETAILS OSCOLPHYS2016 15.1.P.005. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER X Suppose a woman does 600 J of work and 9400 J of heat transfer occurs into the environment in the process. (a) What is the decrease in her internal energy (in kcal), assuming no change in temperature or consumption of food? (That is, there is no other energy transfer.) kcal (b) What is her efficiency (in percent)? % + Additional Materials Reading 4. [0.5/1 Points] DETAILS PREVIOUS ANSWERS OSCOLPHYS2016 15.2.P.012. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Steam to drive an old-fashioned steam locomotive is supplied at a constant gauge pressure of 1.55 x 100 N/m(about 225 psi) to a piston with a 0.205 m radius. (a) By calculating PAV, find the work done (in ]) by the steam when the piston moves 0.805 m. Note that this is the net work output, since gauge pressure is used. (b) Now find the amount of work (in J) by calculating the force exerted times the distance traveled. Is the answer the same as in part (a)? Yes No5. [-/1 Points] DETAILS OSCOLPHYS2016 15.2.P.014. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Calculate the net work output (in ]) of a heat engine following path ABCDA in the figure, where V1 = 0.25 x 10-5 m3 and V2 = 1.0 x 10-3 m3. (10 N/m) 2.6 A 2.0 B 1.0 D 0.6 C V (10-3 m3) J +6. [-/1 Points] DETAILS OSCOLPHYS2016 15.2.P.015. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER What is the net work output (in ]) of a heat engine that follows path ABDA in the figure above, with a straight line from B to D? PA (106 N/m2) A 5.6 5.0 B D 4.0 3.6 C 3.0 6.0 V (10-3 m3) Why is the work output less than for path ABCDA? Explicitly show how you follow the steps in the Problem-Solving Strategies for Thermodynamics. (Submit a file with a maximum size of 1 MB.) Choose File no file selected7. [-11 Points] I DETAILS I OSCOLPHY5201615.3.P.020. I MYNOTES II ASKYOURTEACHER I PRACTICEANOTHER A certain heat engine does 10.0 k] of work and 9.00 k] heat transfer occurs to the environment in a cyclical process. (a) What was the heat transfer (in kJ) into this engine? k.) (b) What was the engine's efficiency (in percent)? % Additional Materials El Reading 8. [-/1 Points] DETAILS OSCOLPHYSZO16 15.3.P.OZ1. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER With 2.95 x 106 J of heat transfer into this engine, a given cyclical heat engine can do only 1.95 x 105 J of work. (a) What is the engine's efficiency? % (b) How much heat transfer (in J) to the environment takes place? J 9. [-/1 Points] DETAILS OSCOLPHYS2016 15.3.P.024. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER The engine of a large ship does 1.85 x 10 J of work with an efficiency of 4.00%. (a) How much heat transfer (in ]) occurs to the environment? (b) How many barrels of fuel are consumed, if each barrel produces 6.00 x 10 J of heat transfer when burned? barrels + Additional Materials Reading 10. [-/1 Points] DETAILS OSCOLPHYS2016 15.4.P.028. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A certain gasoline engine has an efficiency of 34.0%. What would the hot reservoir temperature (in C) be for a Carnot engine having that efficiency, if it operates with a cold reservoir temperature of 180.C? OC11. [-/1 Points] DETAILS OSCOLPHYS2016 15.4.P.029. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A gas-cooled nuclear reactor operates between hot and cold reservoir temperatures of 810 C and 22.0.C. (a) What is the maximum efficiency (in percent) of a heat engine operating between these temperatures? % (b) Find the ratio of this efficiency to the Carnot efficiency of a standard nuclear reactor (47.6%). Eff(a) = Eff ( b ) Additional Materials Reading 12. [-/1 Points] DETAILS OSCOLPHYS2016 15.4.P.033. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A coal-fired electrical power station has an efficiency of 34%. The temperature of the steam leaving the boiler is 540 C. What percentage of the maximum efficiency does this station obtain? (Assume the temperature of the environment is 15C.) %13. [-/1 Points] DETAILS OSCOLPHYS2016 15.5.P.037. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER What is the coefficient of performance of an ideal heat pump that has heat transfer from a cold temperature of -24.0C to a hot temperature of 36.0.C? Additional Materials Reading 14. [-/1 Points] DETAILS OSCOLPHYS2016 15.5.P.041. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) What is the best coefficient of performance for a heat pump that has a hot reservoir temperature of 44.0C and a cold reservoir temperature of -20.0.C? (b) How much heat transfer (in kcal) occurs into the warm environment if 3.60 x 10'J of work (10.0 kW . h) is put into it? kcal (c) If the cost of this work input is 10c/KW . h, how does its cost compare with the direct heat transfer achieved by burning natural gas at a cost of 87.0 cents per therm. (A therm is a common unit of energy for natural gas and equals 1.055 x 108 J.) cost of heat pump cost of natural gas15. [-/1 Points] DETAILS OSCOLPHYS2016 15.5.P.043. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Suppose you want to operate an ideal refrigerator with a cold temperature of -190C, and you would like it to have a coefficient of performance of 6.95. What is the hot reservoir temperature (in C) for such a refrigerator? OC + Additional Materials Reading 16. [-/1 Points] DETAILS OSCOLPHYS2016 15.6.P.048. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER On a hot summer day, 3.00 x 10 J of heat transfer into a parked car takes place, increasing its temperature from 35.5C to 45.2C. What is the increase in entropy (in J/K) of the car due to this heat transfer alone? J/K + Additional Materials Reading 17. [-/1 Points] DETAILS OSCOLPHYS2016 15.6.P.049. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A hot rock ejected from a volcano's lava fountain cools from 230C to 75.0C, and its entropy decreases by 900 J/K. How much heat transfer (in ]) occurs from the rock?18. [-/1 Points] OSCOLPHYSZO16 15.6.P.051. ASK YOUR TEACHER The Sun radiates energy at the rate of 3.80 x 1026 W from its 5500C surface into dark empty space (a negligible fraction radiates onto Earth and the other planets). The effective temperature of deep space is 270C. (Due to the sensitive nature of the calculations, use TKK) = T(C) + 273.15.) (a) What is the increase in entropy (in J/K) in one day due to this heat transfer? J/K (b) How much work (in J) is made unavailable? J Additional Materials El Reading 19. [/1 Points] OSCOLPHYSZO16 15.7.P.058. ASK YOUR TEACHER What percent of the time will you get something in the range from 60 heads and 40 tails through 40 heads and 60 tails when tossing 100 coins? The total number of micro-states in that range is 1.22 x 103". 0/0 20. [-/1 Points] DETAILS OSCOLPHYS2016 15.7.P.059. MY NOTES ASK YOUR TEACHER (a) If tossing 100 coins, how many ways (microstates) are there to get the three most likely macrostates of 49 heads and 51 tails, 50 heads and 50 tails, and 51 heads and 49 tails? (Consult this table.) (b) What percent of the total possibilities is this? %