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Posted by Curbie on March 3, 2009, 12:38 pm
Please log in for more thread options On Tue, 03 Mar 2009 10:36:34 +0000, Tim Jackson
>Curbie wrote:
>> I'm drawn to your use of the word "canceling", I've been using the
>> word "countering" in my notes and I know they're two different words
>> with essentially the same meaning with no real significants to these
>> problems, but any excuse to rewrite my notes will force a much needed
>> review at this point.
>>
>> I'm still muddy on when to apply which ratio of sine, cosine, or
>> tangent to solve for a particular force, I not looking for help with
>> this just "thinking out loud", this answer seems to be the key to
>> solving these problems and feel I will only properly understand its
>> application through study and review.
>>
>> Thank you the efforts of this example, it should be obvious from this
>> post that I still don't get it, but thanks to the efforts a you and
>> others, feel like I am sneaking up on it.
>>
>> Curbie
>> On Mon, 02 Mar 2009 19:02:45 -0600, david.williams@bayman.org (David
>> Williams) wrote:
>>
>>
>>
>The mnemonic I learnt for right triangles was
>
>"Old Horses All Have Old Aunties": O/H A/H O/A
>
>Sine = Opposite/Hypotenuse
>Cosine = Adjacent/Hypotenuse
>Tangent = Opposite/Adjacent
The mnemonic I've been using is:
Some Old Hippy Caught Another Hippy Tripping On Acid
(mnemonic for remembering ratios of sine, cosine and tangent)
Sinb = Opposite / Hypotenuse Cosb = Adjacent / Hypotenuse Tanb =
Opposite / Adjacent
I relate to it better, and therefor the mnemonic easier to remeber.
>
>Where Opposite and Adjacent refer to the side's relationship to the
>angle in question.
>
When putting together my cheesy little spreadsheet to study angles I
ported some Internet Java script equations for the calculations of the
beta angle from ratio of sinb, cosb, or tanb. I think the porting
(which is second nature for me) was faster in reaching the
destination, but I missed something in sort cutting the journey. my
mind just focuses on things it doesn't understand and dumps everything
else on the subject until the details are tidied up. I just have to go
after it again.
>Silly, but I don't forget.
>
>When calculating loading forces for engineering purposes don't forget
>that static forces are only half the story, for example the static
>lateral force on the base is nominally zero, but if it were unrestrained
>the tower wouldn't stand up for long. Winds can produce unequal drag
>above and below the guys (wherever you put them) and can set up bending
>and oscillations which will confound your static calculations. And
>maybe you need to allow for a maintenance man climbing the tower.
>
>That's why engineers tend to use large safety margins.
>
>
>Tim Jackson
Thanks.
Curbie
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