1.2. 3. 4. 5. Problem Set No. 2 Deadline of Submission: July 13, 2015 (Monday) A man goes to a traditional market to buy a steak for dinner. He finds a 12-oz steak (1 lbm = 16 oz) for $3.15. He then goes to the adjacent international market and finds a 320-g steak of identical quality for $2.80. Which steak is the better buy? A tank contains a mixture of 20 kg of nitrogen and 20 kg of carbon dioxide. The total tank volume is 20 m 3. Determine the density and specific volume of the mixture. Someone proposes a new absolute temperature scale in which the boiling and freezing points of water at atmospheric pressure are 500°X and 100°X, respectively. Develop a relation to convert this scale to degree Celsius. A diver descends 100 m to a sunken ship. A container is found with a pressure gage reading 100 kPa (gage). Atmospheric pressure is 100 kPa. What is the absolute pressure of the gas in the container? A beer barrel has a mass of 10 kg and a volume of 20 liters. Assuming the density of beer is 1000kg/m 3, determine the total mass and weight of the barrel when it is filled with beer. 6. Find the area of the piston on which the 45 kN force act. 7. The vertical frictionless piston-cylinder shown below contains a gas at an unknown pressure. The piston has a mass of 10 kg and a cross-sectional area of 75cm2. The spring exerts a downward force of 100 N on the piston, and atmospheric pressure is 100 kPa. Determine the pressure of the gas. 8. Steam is held in two compartments (A and B) separated by a membrane. The total volume is 777 ft 3, and the volume of compartment B is 280 ft 3. The specific volume of the steam in B is 9.5 ft 3/lbm. The membrane breaks, and the resulting specific volume is 12.75 ft3/lbm. Determine the original specific volume in compartment A. 9. A tank has a vacuum gage attached to it indicating 25 in Hg (vacuum) where atmospheric pressure is 14.5 psia. Determine the absolute pressure inside the tank tank. 10. The lower half of a 10-m-high cylindrical container is filled with water (ρ = 1000 kg/m 3) and the upper half with oil that has a specific gravity of 0.85. Determine the pressure difference between the top and bottom of the cylinder. 11. A hiker is carrying a barometer that measures 29.92inHg absolute at the base of the mountain. The barometer reads 25.5inHg absolute at the top of the mountain. The average air density is 0.076 lb m/ft3, the gravitational acceleration remains constant at 32.174 ft /s2. What is the mountain’s height? 12. A 3 kg plastic tank has a volume of 0.2m 3 is filled with liquid water. Assuming the density of water is 1000kg/m 3. Determine the weight of the combined system. 13. Determine the mass and weight of air contained in a room whose dimensions are 6m x 6m x 8m. Assume the density of air is 1.16kg/m3. 14. Consider a 70 kg woman who has a total foot imprint area of 400cm 2. She wishes to walk in the snow, but the snow cannot withstand pressure greater than 0.5 kPa. Determine the minimum size of the snow shoes needed (imprint area per shoe) to enable her to walk on the snow without sinking. 15. A vacuum gage connected to a tank reads 30 kPa at a location where the barometric reading is 755 mmHg. Determine the absolute pressure in the tank. Take ρHg=13,590kg/m3. 16. Determine the pressure exerted on a diver at 30m below the free surface of the sea. Assume a barometric pressure of 101 kPa and a specific gravity of 1.03 for seawater. 17. A cubic meter of water at room temperature has a weight of 9800 N at a location where g=9.8m/s 2. What is its specific weight and its density at a location where g=9.77m/s2? 18. An 9-m3 tank of nitrogen is separated by a membrane into two sections. Section A has an initial density of 1.667 kg/m 3 and section B has a mass of 6 kg. After the membrane is broken, the density is found to be 1.778kg/m 3. Find the initial density of the gas in section B in kg/m3. 19. A vertical, frictionless piston–cylinder device contains a gas at 250 kPa absolute pressure. The atmospheric pressure outside is 100 kPa, and the piston area is 30 cm2. Determine the mass of the piston. 20. A hydraulic lift is to be used to lift a 2500 kg weight by putting a weight of 25 kg on a piston with a diameter of 10 cm. Determine the diameter of the piston on which the weight is to be placed.