Thursday, August 21, 2008

TE 303 - Welcome to the LearnThermo Blog

For each homework problem that Dr. Pasquinelli assigns, I will post the problem statement on this blog. If you have any questions about the problem, click on the small red "comments" at the end of the problem statement. This will take you to a page where you can see all of the questions that you classmates asked, as well as my answers. If nothing you find on this page answers your question, then you can type in a new question for me. You should probably choose the "Name/URL" option for your identity. This will let you make up any name you like. This helps me state which question I am answering. But you don't need to use your real name. That way you and I can interact and no one will know who you are.

I will check this blog twice per day during the week, but you cannot rely on me on the weekend. I will probably only check the blog on Sunday night.

BUT I encourage you to answer each others questions ! You don't really, really (Shrek) understand something until you can explain it to someone else. So, try to help someone. It is anonymous. You might get a deeper understanding of the problem, and helping someone learn is a good thing to do.

I have blogged (with my students) many of the problems Dr. Pasquinelli will use in this course. You can search this blog to see the questions and answers that are already posted. I suggest you focus your search on March through June 2007.

You might also consider the supplemental example problems for Thermo-CD. These are posted on my LearnThermo webiste. Here is the link that goes directly to the additional example problems: Examples

I look forward to working with you.

Dr. B

TE 303 - HW #1, P1 - Mass, Force, Density and Acceleration - 10 pts

A closed system consists of 0.5 lbmole of liquid water and occupies a volume of 0.145 ft3. Determine the weight of the system, in lbf, and the average density, in lbm/ft3, at a location where the acceleration of gravity is g = 30.5 ft/s2.

TE 303 - HW #1, P2 - Mass, Weight and Acceleration - 6 pts

The weight of an object on an orbiting space station is measured to be 42 N based on an artificial acceleration of 6 m/s2. What is the weight o f the object, in N, on Earth, where g = 9.81 m/s2 ?

TE 303 - HW #1, P3 - NOx Emissions: UNITS - 6 pts

A typical car driven 12,000 miles/year emits to the atmosphere about 11 kg/year of NOx (nitrogen oxides), which causes smog in cities. Natural gas burned in a home furnace emits about 4.3 g of NOx per therm and electric power plants emit about 7.1 g NOx per kWh of electricity produced. Consider a household that has two cars and consumes 9,000 kWh of electricity and 1,200 therms of natural gas. Determine the amount of NOx emission to the atmosphere per year for which the household is responsible.

TE 303 - HW #1, P4 - Temperature Conversions: Celsius to Fahrenheit - 12 pts

Convert the following temperatures from oC to oF.
a.) 21 oC
b.) -17.78 oC
c.) -50 oC
d.) 300 oC
e.) 100 oC
f.) -273.15 oC

TE 303 - HW #1, P5 - Temperature Conversions: Fahrenheit to Celsius - 12 pts

Convert the following temperatures from oF to oC.

a.) 212 oF
b.) 68 oF
c.) 32 oF
d.) 0 oF
e.) -40 oF
f.) -459.67 oF

TE 303 - HW #1, P6 - Temperature Change - 6 pts

The temperature of a system rises by 72oC during a heating process. Express this temperature increase in Kelvins and degrees Rankine.

TE 303 - HW #1, P7 - Absolute and gauge Pressures - 15 pts

Tank A lies inside of Tank B, as shown in the figure. Pressure gauge A is located inside Tank B and reads 1.4 bar. Both tanks contain air. The manometer connected to Tank B contains mercury (r = 13.59 g/cm3). The manometer reading is h = 20 cm, atmospheric pressure is 101 kPa and g = 9.81 m/s2. Determine the absolute pressures inside Tank A and Tank B in kPa.

TE 303 - HW#1, P8 - Differential, Multi-Fluid Manometer - 18 pts

Fresh water and seawater flowing in parallel, horizontal pipelines are connected to each other by a double u-tube manometer, as shown in the figure. Determine the pressure difference between the two pipelines in kPa. Assume the density of seawater to be 1035 kg/m3. Can the air column be ignored in this analysis ?