PCB/PDB1043
Assignment # 1

Submission Date: 15 Oct. 2014

BASIC CONCEPTS OF THERMODYNAMICS & ENERGY TRANSFER BY HEAT, WORK & MASS 1. What is the difference between intensive and extensive properties? Separate the list P, F, V, v, ρ, T, a, m, L, t and V into intensive, extensive and non-properties. Is it possible to convert one extensive property to an intensive one? 2. You dive 15 ft down in the ocean. What is the absolute pressure there? 3. What is the smallest temperature in degrees Celsius you can have? Kelvin? 4. The “standard” acceleration (at sea level and 45° latitude) due to gravity is 9.80665 m/s2. What is the force needed to hold a mass of 2 kg at rest in this gravitational field? How much mass can a force of 1 N support? 5. A gasoline line is connected to a pressure gage through a double-U manometer as shown in the figure. If the reading of the pressure gage is 370 kPa, determine the gage pressure of the gasoline line.

6. A tank has two rooms separated by a membrane. Room A has 0.5lbm air and volume 18ft3, room B has 30ft3 air with density 0.05lbm/ft3. The membrane is broken and the air comes to a uniform state. Find the final density of the air. 7. A hydraulic lift has a maximum fluid pressure of 80. What should the piston-cylinder diameter be so it can lift a mass of 1600 lbm? 8. Electric power is to be generated by installing a hydraulic turbine-generator at a site 160 mbelow the free surface of a large water reservoir that can supply water at a rate of 3500 kg/ssteadily. Determine the power generation potential. 9. Consider a river flowing toward a lake at an average velocity of 3 m/s at a rate of 500 m3/s at a location 90 m above the lake surface. Determine the total mechanical energy of the river water per unit mass and the power generation potential of the entire river at that location.

PCB/PDB1043

Submission Date: 15 Oct. 2014