Inter American University of Puerto Rico
Bayamon Campus
Department of Mechanical Engineering
MECN 4201 – Thermodynamics I
Spring 2010
Professor: Omar Meza
Nombre:
ID:
Due Date: 01-Feb-2010
Homework1: Introduction and Basic Concepts
Thermodynamics An Engineering Approach
Y. A. Cengel M. A. Boles – Sixth Edition
1. Problem 1-8E: A man weighs 180 lbf at a location where g= 32.10 ft/s2.
Determine his weight on the moon, where g= 5.47 ft/s2.
2. Problem 1-9: Determine the mass and the weight of the air contained in a
room whose dimensions are 6 m X 6 m X 8 m. Assume the density of the
air is 1.16 kg/m3.
3. Problem 1-24: What is a quasi-equilibrium process? What is its importance
in engineering?
4. Problem 1-34E: Consider a system whose temperature is 18 oC. Express
this temperature in R, K and oF.
5. Problem 1-45E: The maximum safe air pressure of a tire is typically
written on the tire itself. The label on a tire indicates that the maximum
pressure is 35 psi (gage). Express this maximum pressure in kPa.
6. A U-manometer is connected to a closed tank as shown in the Figure 1.
The air pressure in the tank is 120 Pa and the liquid in the tank is oil
(specific weight is 12000 N/m3). The pressure at point A is 20 kPa.
Determine: (a) the depth of oil z, and (b) the differential reading h on the
manometer
Figure 1
7. The inverted U-tube manometer of Figure 2 contains oil (SG=0.9) and the
water as shown. The pressure differential between pipes A and B, pA-pB, is
-5 kPa. Determine the differential reading h.
Figure 2