tag:blogger.com,1999:blog-7383244142918713942024-03-13T06:07:56.621-07:00PE Exam (Civil) using HP 33s and 35SJChttp://www.blogger.com/profile/00547353371824900620noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-738324414291871394.post-18817538942351309682012-03-10T07:50:00.002-08:002012-03-10T07:59:47.739-08:00Quadratic EquationJust came across with a program for quadratic equations. I am not sure where the code is coming from but it certainly works. It will ask you the values A, B and C from the formula Ax^2+Bx+C=0<br />
<span style="background-color: white; font-family: monospace; white-space: pre;"><br />
</span><br />
<span style="background-color: white; font-family: monospace; white-space: pre;">Blue key, R/S [PRGM]</span><br />
<span style="background-color: white; font-family: monospace; white-space: pre;"> </span><br />
<pre style="background-color: white;">Line Instruction Description, input.
______________________________________________________________
Q001 LBL Q , program's name "Q"
Q002 CF 10 , Yellow key, up arrow [FLAGS], 2CF, 10
Q003 INPUT A
Q004 INPUT B
Q005 INPUT C
Q006 -B÷(2xA)
Q007 ENTER
Q008 ENTER
Q009 B^2-4xAxC
Q010 x>=0?
Q011 GTO Q017
Q012 +/-
Q013 sqrt ;press k key
Q014 i
Q015 x
Q016 GTO Q018
Q017 sqrt
Q018 2xA
Q019 ÷
Q020 +
Q021 x<>y
Q022 LASTx
Q023 -
Q024 RTN </pre><br />
<span style="background-color: white; font-family: monospace; white-space: pre;"> Execute the program: XEQ Q ENTER. Enter A, B and C according to the equation Ax^2+Bx+C=0. It will show both solutions in x and y registers.</span>JChttp://www.blogger.com/profile/00547353371824900620noreply@blogger.com2tag:blogger.com,1999:blog-738324414291871394.post-25171012930685885232011-08-09T12:11:00.000-07:002011-09-21T10:32:37.878-07:00CONSTRUCTION: Engineering Economics<div dir="ltr" style="text-align: left;" trbidi="on"><b>The Time Value of Money</b><br />
<br />
Press the EQN key, then follow this:<br />
<br />
A x 100 x ( 1 - ( 1 + I ÷ 100 )^ -N) ÷ I + F x ( 1 + I ÷ 100 ) ^ -N + P<br />
<br />
A= uniform amount per interest period<br />
I=interest rate<br />
N= # of periods<br />
F=Future Value FV<br />
P=Present Value PV (Benefit)<br />
<br />
<i>For<b> HP 35S</b> users, when input -N use the "+/-" key instead of the subtraction key "-"</i><br />
<br />
<b>Question</b>: A city engineer is deciding which of two alternatives to select.<br />
<br />
Alternative Cost Annual Benefit Salvage Useful Life<br />
A $48,000 $13,000 $0 6 yrs<br />
B $40,000 $12,000 $0 6 yrs<br />
<br />
If the interest rate is 10% per year, the Benefit-Cost analysis ratio of the alternative to be selected is most nearly:<br />
<br />
a. 1.125<br />
b. 1.179<br />
c. 1.307<br />
d. 1.387<br />
<br />
<br />
Alternative A: <br />
Press the key SOLVE and select the variable you are looking for, in this case the Present Value "P" , then select the equation pressing EQN and selecting the pv equation<br />
A? 13,000; press "R/S"<br />
I? 10; press "R/S"<br />
N? 6; press "R/S"<br />
F? 0; press "R/S"<br />
P? press "R/S"<br />
The screen will show "RUNNING"<br />
then the answer is 56,618.4 which is the present value of the investment.<br />
the initial cost is $48,000<br />
the Benefit-Cost analysis ratio of alternative A is 56,618.4/48,000 = 1.18%<br />
<br />
Same methodology for Alternative B => present value is $52,263<br />
<br />
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">the Benefit-Cost analysis ratio of alternative B is 52,263/40,000 = 1.31%</div><div><br />
</div><div><b>Answer= C</b></div><br />
<b>Question:</b> A residential community will need to add an additional unit to the existing water treatment plant when the population reaches 40,000. An average of 6,000 new residents are moving into the community each year. The estimated birthrate for the community is 8 per 1,000 and the death rate is 14 per 1,000 resulting in a negative annual increase of -0.6%. The number of years before the second unit is needed for the new water treatment plant is most nearly:<br />
a. 6.57<br />
b. 6.78<br />
c. 6.91<br />
d. 6.87<br />
Solution: The population must reach 40,000 before the additional unit is needed, so that F = 40,000. The number of new residents expected each year is 6,000, therefore, A = 6,000.<br />
The residents should have a natural rate of negative annual increase of -0.6%, i = -0.006.<br />
Use the F/A equation as follows and solve for n:<br />
F = (A (1+i)^n – 1)/i<br />
n = (ln( F i / A + 1))/(ln (1+i))<br />
n = (ln (40,000 x (-0.006)) / 6,000] + 1))/(ln (1 - 0.006))<br />
n = 6.78<br />
<br />
Using the equation it gives you the same result: N=6.78323<br />
<br />
<br />
</div>JChttp://www.blogger.com/profile/00547353371824900620noreply@blogger.com1Manhattan, NY 10003, USA40.7322535 -73.9874105000000140.7238835 -73.995965500000011 40.7406235 -73.978855500000009tag:blogger.com,1999:blog-738324414291871394.post-59320548078117776632011-08-08T06:03:00.000-07:002011-08-08T06:29:06.144-07:00RPN mode<div dir="ltr" style="text-align: left;" trbidi="on">First things first. It is clear that we own HP calculators because we are familiar with the Reverse Polish Notation (RPN). Programs are better in RPN mode than the traditional algebraic mode because they execution is faster and it uses less memory.</div>JChttp://www.blogger.com/profile/00547353371824900620noreply@blogger.com0