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03-18-2011
06:57 AM

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03-18-2011
06:57 AM

Problem with units

Hi,

I'm having the following issue with the units in mathcad15:

L:=20.76m

Then when I go to repeat L later in my sheet it comes out as L=0.

Anyone got any ideas how I can solve this issue? I'm having the same problem even when I change L to Beam for example.

Thanks

Mike

Solved! Go to Solution.

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03-18-2011
07:53 AM

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03-18-2011
07:53 AM

On page 7 of 9 you have defined m as zero.

Try not to use varibles names which are units. Just call it m1 or something similiar.

Mike

10 REPLIES 10

03-18-2011
07:08 AM

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03-18-2011
07:08 AM

No, have a look below. Can you post the worksheet?

Mike

03-18-2011
07:46 AM

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03-18-2011
07:46 AM

Mike,

I've added the sheet, the problem is on page 10 and highlighted in red.

Cheers,

Mike

03-18-2011
07:53 AM

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03-18-2011
07:53 AM

On page 7 of 9 you have defined m as zero.

Try not to use varibles names which are units. Just call it m1 or something similiar.

Mike

03-18-2011
07:59 AM

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03-18-2011
07:59 AM

Ahh that never occurred to me!

Thanks!!

12-31-2019
01:09 AM

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12-31-2019
01:09 AM

Please help me to check where i am doing wrong.

12-31-2019
03:42 AM

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12-31-2019
03:42 AM

That depends on what you think is 'wrong'. What did you expect as value for P or X?

You're using units rpm and s. Do you know what they mean?

In your formula for calculating P (or X) you use a division by 60 and a multplication with 2pi. What is that for?

Have you checked the ratio of X/P?

Success!

Luc

12-31-2019
04:00 AM

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12-31-2019
04:00 AM

As per the answer of X & P..

Values in P : N=50rpm & T= 50 sec

Answer should be : (2 * pi * N * T)/60=261.8333

but it getting : 27...

If i put the numbers instead of defined parameters, answer is right.

then why the answers of X and P are not matching..?

12-31-2019
04:48 AM

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12-31-2019
04:48 AM

Looks like you did not understand the unit rpm (revolutions per minute). The factor 2 pi /60 is already part of it.

So get rid of that factor and simply calculate N*T

For future questions open a new thread and keep in mind to always also attach your worksheet(s).

12-31-2019
05:57 AM

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12-31-2019
05:57 AM

Thank you Sir..!!

Got it.

12-31-2019
04:55 AM

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12-31-2019
04:55 AM

You did not answer all questions that I formulated. This means that you do not understand yet the usage of units...

Do you know what '50 rpm' means? Note that it is VERY different from '50'.

Why does your fomula for the calculation of P use a 2pi multiplication and a division by 60?

(I see that in the mean time Werner explained the situation. I was trying to get you intrigued into finding out yourself what is going on.)

Success!

Luc