Question

Please answer question 6. thanks

1. A 7 kg lead sphere that has 35 °C temperature falls through the air. When the sphere is 15 m above the ground, its speed is 20 m/s. Suppose that when the sphere hits the ground, 75% of its kinetic energy converts to heat that raises its temperature. Specific heat capacity of lead c = 128 J/kg.°C, g=9.8 m/s. A. Setup with a labeled diagram. b. Write down in symbols the energy equation. c. Find the final temperature T of the bullet. 2. In an insulated tank, there is a 3.5 kg glass vase at 26 °C in which we pour 6 kg of water that has 53 °C temperature. Specific heat capacities: Cw = 1 kcal/kg.°C, Cg = 0.2 kcal/kg.°C. A. Setup with a labeled diagram. b. Write down the energy equation in algebraic terms. c. From the energy equation, obtain the final temperature T. 3. A gas in a cylinder has 2.8 atm pressure, 4 lt volume, and 25 °C temperature. We compress this gas to 3.2 lt and cool it down to 20 °C temperature. A. Setup with two labeled diagrams. b. Calculate the final pressure of the gas in atm. 4. A quantity of O2 gas has a temperature of 35 °C. The atomic weight of O is 16. A. Setup with a schematic diagram showing the speeds of the O2 molecules. b. Find the mass of the O2 molecule in kg. c. Calculate the average speed (Vrms) of the O2 molecules. 5. A quantity of 66 g Neon gas at 327°C has 80 lt volume. The gas is heated and expands isothermally (at constant temperature) to 500 °C. The atomic weight of Ne is 20. A. Setup with a labeled diagram. b. Compute the Ne mass in moles. c. Calculate the work done by the expanding Ne gas. 6. The hot reservoir of an ideal heat engine has 600 °C temperature, and its cold reservoir has 27 °C temperature. The engine produces 35,000 J of mechanical work. A. Setup with a schematic diagram. b. Calculate the efficiency e of the engine. c. Calculate the heat energy Qh consumed by the engine and the heat energy Qc that the engine released in the cold reservoir.

Answer 1

(A) Hot Reservoir Cold Resenvoir TH = 600'c Te=27°C = 35000 J (B ) = 0•656 65.6°% Tc 277273 Or | - 660+ 273 TH (C) Qu- 35o0 0- 656 = 53324.6 J Answer & 8, = 3n -W = 53324- 6 - 3500 18324.6 J Annwer