Searching \ for '[OT]: Help with math problem' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/method/math.htm?key=math
Search entire site for: 'Help with math problem'.

Exact match. Not showing close matches.
PICList Thread
'[OT]: Help with math problem'
2002\10\02@141834 by Quentin

flavicon
face
First, how do you show superscript in text messages?
I'll be using HTML tags to indicate superscript (<sup></sup>)

I can't the correct result from this equation:
C = (0.09*E*t <sup>2</sup> /K <sup>4</sup> )<sup>1/3</sup>
If E=100, t=500 microsecs (500E-6), and K=13
then:
C=[0.09*100*(500E-6)<sup>2</sup>/(13)<sup>4</sup>]<sup>1/3</sup>
 is what?
The example gives the answer to be 0.199E-3 Farad

I keep on getting 0.422E-3 Farad.
Where did I go wrong or is it them?

Maybe it is getting too late here.

Thanks
Quentin

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email spam_OUTlistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body


2002\10\02@144949 by Jennifer L. Gatza

flavicon
face
To denote an exponent, use the caret (^):

C = [(0.09 * E * t^2) / (K^4)]^1/3

 = [(0.09 * 100 * (5e-4)^2) / (13^4)]^1/3

The answer I get is 4.29e-5.

If t = 5us instead of 500us, I get .199e-4 (or 1.99e-5).

My two troubleshooting questions:
Are you sure of your exponent values (e-3 vs. e-4)?
Are you sure of the values you are plugging into the equation? (esp. t)

BTW, textbooks are occasionally wrong.  Then again, so am I.  :)

Jen

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body


2002\10\02@153628 by David Minkler

flavicon
face
Quentin,

If I read your HTML tags correctly, your result is correct (numerically,
dimensional analysis doesn't work).  Commonly, I've seen carat ^ or
double asterisk ** used to indicate exponentiation.  As always,
parentheses can be used to clarify.

Regards,
Dave

Quentin wrote:
{Quote hidden}

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam.....mitvma.mit.edu with SET PICList DIGEST in the body


2002\10\02@164713 by Quentin

flavicon
face
> The answer I get is 4.29e-5.
I get 0.429e-3. I got 0.422e-3 in my previous post because I used 0.334
as a replacement for 1/3.

> If t = 5us instead of 500us, I get .199e-4 (or 1.99e-5).
Yes, I looked back in the document and it stated that t should be in the
range of 5 to 50 microsecs.

So the text example is incorrect, I can merrily plod along with my own
values.
Thanks Jen, and Dave for confirming it.

Quentin

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email EraseMElistservspam_OUTspamTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body


More... (looser matching)
- Last day of these posts
- In 2002 , 2003 only
- Today
- New search...