While riding his bicycle, Jans does 7.5 E7 J of work and gives off 4.3 E7 J of heat. What is the change in Jan's internal energy?  + 3.2 E 7 J −3.2 E 7 J −11.8 E 7 J +11.8 E 7 J

A 220-lb athlete drinks a glass of soda (125 calories) and walks up to the top of a Library Building. What is the change in his internal energy, assuming the only heat transfer is the 125 calories from the soda drink, and the only work done by the athlete is lifting his own weight to the 6th floor? Assume 3m per floor.

(13 %) Problem 4: Consider the change in the internal energy of a system. What is the change in the internal energy, in joules, of a system that does 4.575 x 105 J of work, while 3.05 x 106 J of heat is transferred into the system and 7.95 x 106 J of heat is transferred from the system to the environment? AU= Grade Summary Deductions

*95. Even at rest, the human body generates heat. The heat arises because of the body's metabolism-that is, the chemical reac- tions that are always occurring in the body to generate energy. In rooms designed for use by large groups, adequate ventilation or air conditioning must be provided to remove this heat. Consider a classroom containing 200 students. Assume that the metabolic rate of generating heat is 130 W for each student and that the heat accumulates during a fifty-minute lec- ture. In addition, assume that the air has a molar specific heat of Cy = R and that the room (volume = 1200 m², initial pressure = 1.01 × 10° Pa, and initial temperature = 21 °C) is sealed shut. If all the heat generated by the students were absorbed by the air, by how much would the air temperature rise during a lecture?

8000 J of heat from a hot reservoir is put into a reversible (Carnot) heat engine whose hot and cold reservoirs are at 600 K and 150 K respectively. How much work does the engine do?

A) An aircraft piston engine that burns gasoline (heat of combustion 5.0×107 J/kg) has a power output of 1.50×105 W. How much work does this engine do in 1.00 h? B) This engine burns 43 kg of gasoline per hour. How much heat does the engine take in per hour? C)  What is the efficiency of the engine?

How much heat, in joules, is transferred into a system when its internal energy decreases by 165 J while it was performing 29.5 J of work? Q = - 189.51

3 moles of an ideal polyatomic gas initially with a volume of 2 m3 and a temperature of 3000C is compressed isothermally to 1/3rd its initial volume. How much heat must be added to the system during this compression? a) 15.7 kJ                               b) -15.7 kJ                         c) 8.2 kJ                             d) – 8.2 kJ

27. This problem compares the energy output and heat transfer to the environment by two different types of nuclear power stations—one with the normal efficiency of 34.0%, and another with an improved efficiency of 40.0%. Suppose both have the same heat transfer into the engine in one day,  2.50×1014J . (a) How much more electrical energy is produced by the more efficient power station? (b) How much less heat transfer occurs to the environment by the more efficient power station? (One type of more efficient nuclear power station, the gas-cooled reactor, has not been reliable enough to be economically feasible in spite of its greater efficiency.)