20. n moles of ideal gas of pressure P and volume V undergoes an irreversible expansion with final pressure is P/3 and volume 3V. With R is the universal gas constant, find the entropy exchange of the process.
(A)0
(B)nR ln3
(C)3 nR
(D)nR ln6
(E)6 nR

複選題16. A bubble having a volume of 1.00 cm3 is released from the bottom of a water tank where the depth is 10.0 m. What will the volume of the bubble be when it reaches the surface? The temperature of the water at the surface is 27.0 °C, whereas it is 57.00C at the bottorn. (The density of water is 1.00 x 103 kg/m3. Take g = 10 m/s2 and 1 atm = 1.0 x 105 Pa) (AB)1.10 cm3 (AC) 2.20 cm3(AD)1.45 cm3(AE)1.65 cm3(BC)1.35 cm3 (BD)一律送分

17. Liquid metal of mass m kg at 500 K is mixed with the same liquid metal of same mass at 1500 K. Given the specific heat of the metal is c cal/K, find the change in entropy (in cal/K) of the system. Take In 2 = 0.70, In 3 = 1.10, In 4 =1.40, In 5 = 1.61. (A)+2.0 mc(B) +0.6mc(C)-1.0 mc(D) +0.3 mc(E) -0.21 mc

18. A 5.23-g pebble is dropped from a 300-m building. If it reaches a terminal velocity of 40 m/s, and the rest of the energy is converted to heating the coin, what is the change in temperature (in °C) of the coin? (The specific heat of pebble is 400 J/kg.°C Take g = 10 m/s2. )(A)8.5 (B) 2.8 (C) 5.5 (D)21 (E)0.5

19. While temperature is kept constant, if consider only translational and rotational motion, what is the total energy of 1 liter of nitrogen gas with pressure of I atm (take 1 atm=105 Pa)? (A)0.1kJ (B)0.15kJ(C)0.2kJ(D)0.25 kJ(E) 0.35 kJ

複選題21. An object hangs from a spring balance. The balance indicates 30 N in air and 20 N when the object is submerged in water. What mass of the object would weigh 20N by the balance when the object is submerged in a liquid with a density that is half that of water? Take g = 10 m/s2. (AB)20N (AC)25N(AD)30N(AE)35N (BC)40N (BD)一律送分

22. Water is streaming downward from a faucet opening with an area of . It lcaves the faucet with a specd of 5.0 m/s. The cross-sectional area of the stream 0.55 m below the faucet is how many : (Take g = 10 m/s2. ) (A)1.5(B)2.0 (C)2.5 (D)3.0(E) 3.5

23. A police crime lab is trying to determine whether someone was murdered or died as a result of an accident. He was struck in the temple by a 4.00 kg sculpture that is alleged to have fallen off a bookcase. The sculpture presumably fell a distance of 1.80 m and the corner that struck him had an area of 0.240 cm2. If the time for the sculpture to stop was 1.00 ms, take g = 10.0 m/s, the pressure on his temple, in N/m2, was (A)1.00x104.(B) 1.50x 105.(C) 1.50x 106(D) 1.00 x 109. (E) 1.25 x 109

24. A venturi tube may be used as the inlet to an automobile carburetor. If the 2.0-cm diameter horizontal pipe narrows to a 1.0-cm diameter, what is the pressure drop in the constricted section for an airflow of 2.0 m/s in the 2.0-cm section? (p= 1.2 kg/m3.) (A)70Pa(B)85Pa(C)95Pa (D)20 Pa (E) 36 Pa

25. Determine the minimum area of a flat ice floe 1.0 meter thick if it is to support a 2 000-kg car above seawater. ( = 920 kg/m3, = 1 020 kg/m3.) (A)20m2(B)40m2 (C)60m2(D)80m2 (E) 100m2

26. At what rate is thermal energy being generated in the 2R-resistor when ε = 12 V and R = 3.0 Ω? (A)12 W (B) 24 W (C) 6.0 W (D)3.0 W (E)1.5 W