Engineering Fundamentals: An Introduction to Engineering, 4th ed.c

Problems 497

Summary

Now that you have reached this point in the text you should:

• know that MATLAB is a tool that can be used to solve engineering problems. Moreover, you
  can use MATLAB to present the results of an analysis in chart form. You can input your own
  formulas or use the built-in functions provided by MATLAB.


• know how to edit the content of a MATLAB file.


• be familiar with MATLAB’s built-in functions.


• know how to import data files into MATLAB.


• know how to create a proper engineering chart using MATLAB.


• know how to perform matrix computations with MATLAB.


• be familiar with MATLAB’s curve-fitting capabilities.


• be familiar with MATLAB’s symbolic mathematics capabilities.

Problems

15.1. Using the MATLAB Help menu, discuss how the fol-

lowing functions are used. Create a simple example,

and demonstrate the proper use of the function.

a. ABS (X)

b. TIC, TOC

c. SIZE (x)

d. FIX (x)

e. FLOOR (x)

f. CEIL (x)

g. CALENDAR

15.2. In Chapter 10, we discussed fluid pressure and the

role of water towers in small towns. Use MATLAB

to create a table that shows the relationship between

the height of water above ground in the water to

wer and the water pressure in a pipeline located

at the base of the water tower. The relationship is

given by

where

P water pressure at the base of the water tower

in pounds per square foot (lb/ft

2

)

rdensity of water in slugs per cubic foot (r

1.94 slugs /ft

3

)

gacceleration due to gravity (g32.2 ft /s

2

)

hheight of water above ground in feet (ft)

Create a table that shows the water pressure in lb/in

2

in

a pipe located at the base of the water tower as you vary

the height of the water in increments of 10 ft. Also, plot

the water pressure (lb/in

2

) versus the height of water

in feet. What should the water level in the water tower

be to create 80 psi of water pressure in a pipe at the

base of the water tower?

15.3. As we explained in Chapter 10, viscosity is a measure

of how easily a fluid flows. The viscosity of water can

be determined from the following correlation.

where

mviscosity (N/s m

2

)

T temperature (K)

c 1 2.414  10

 5

N/s m

2

c 2 247.8 K

c 3 140 K

Using MATLAB, create a table that shows the viscos-

ity of water as a function of temperature in the range of

0 C (273.15 K) to 100C (373.15 K) in increments of

5 C. Also, create a graph showing the value of viscos-

ity as a function of temperature.

mc 110

a

c 2

Tc 3

b

Prgh

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