Mike,

You can enter the scientific notation in the Windows calculator as follows:

1.  From the view menu select "Scientific"
2.  Press the "X" key, this allows you to enter a number in scientific 
notation.
3.  To enter a negative power of 10, change the sign with the "F9" key prior 
to entering the power.

So for example if you wanted to enter 50 micro henrys, you would enter the 
following sequence:

"50" "X" "F9" "6"

The display on your calculator would show the following:

"50.E-6"

To take the square root of the L multiplied by C do the following:

1.  Using the JAWS cursor, navigate to a button labeled "INV" near the top 
of the calculator in the row above the 7 8 9 and do a left mouse click. 
This button does an inverse function on the next key press and only remains 
on for the key pressed immediately following the press of the "INV" button.

2.  Navigate down the calculator keyboard with the JAWS cursor and locate a 
button labeled "X^2" and left click on this button and you will have taken 
the    square root of the number in the display.  The "X^2" is in the bottom 
row of buttons.  The "X^2" button squares a number if not proceeded by the 
press of the "INV" button first.

Try this square root function on several numbers that you know the square 
root of such as 100, 81, 64, 16, or 4 so you know you are doing it 
correctly.

I hope this helps.

73's

Howard #3, W A 9 Y B W

----- Original Message ----- 
From: "Mike Keithley" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, January 20, 2012 9:45 PM
Subject: Re: Math Help


> This sounds right, but  I know that trying to enter this into a speech 
> calculator I have is impossible because it won't accept scientific 
> notation. And I couldn't figure out how to do it in the windows calculator 
> either.
>
> ----- Original Message -----
> From: David thurmond <[log in to unmask]>
> To:  [log in to unmask]
> Date: Wednesday, Jan 18, 2012 05:29:31
> Subject: Math Help
>
>>
>>
>> All,
>>
>> Sorry for my previous post, I previously stated that 1 picofarad = 1 x
>> 10 ^ -9 Farad, which is why my calculation was wrong.  I also screwed
>> up entering the units on the calculator, so I should have
>> double-checked my work!  I believe this is correct, however:
>>
>> The formula is:
>>
>> Resonant Frequency (Hz) = 1 / (2pi * sqrt(L C)
>>
>> where L is in Henries and C is in Farads.  So, in your example:
>>
>> 1.  Convert 50 microHenries to Henries, 1 microHenry = 1 x 10^-6
>> Henries, so 50 microHenries = 5.0 x 10^-5 Henries.
>> 2.  Convert 200 picofarads to Farads.  1 picofarad = 1 x 10^-12 farads,
>> so 200 picofarads = 2 x 10 ^ -10 Farads.
>> 3.  Now, plug into the formula:
>> F = 1 / (2pi * sqrt (5 x 10^-5 times 2 x 10 ^ -10)
>> = 1 / 2pi * 1 x 10^-7
>> =1591557 Hz
>>
>> Hopefully this is correct now, and hopefully I did more than just
>> muddy up the waters beyond all hope!  My apologies!
>>
>> So you can see, the worst part of this problem is getting the units
>> correct, at least for me.
>>
>> 73,
>>
>> David Thurmond, KK4ADV