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celect
Jun21-05, 04:39 PM
If I'm given v=50 sin(5000t)
how do I determine the frequency or amplitude?

Can someone direct me to a source?
thank you

Delta
Jun21-05, 05:01 PM
http://www.physicsforums.com/showpost.php?p=554607&postcount=5

celect
Jun21-05, 09:05 PM
do I take the sin of 50 then times that by 1/5000t?

EvLer
Jun21-05, 10:45 PM
just match your equation against what's in the link.
amplitude value precedes "sin(...)"

hint: phita (phase angle) is zero in your case

willib
Jun22-05, 03:30 PM
50 is your amplitude
5000 is your radian frequency in rad/sec

celect
Jun22-05, 05:19 PM
Vs = A*sin({\omega}t + {\phi})+C


this formula states Vs =

Using the information I'm given

50 * sin(wt + 0) + C

is that the sin of 5000t
I'm confused on this I never used this type of equation before.

Delta
Jun22-05, 06:13 PM
Compare your equation

V = 50*sin(5000t)

with

Vs = A*sin({\omega}t + {\phi})+C

You can see that A is 50 and \omega is 5000. \Phi and C are zero.

As shown in my definition, A is the amplitude and \omega is equal to 2{\pi}f

So you can therefore determine the amplitude value and with a little calculation the frequency as well.

celect
Jun22-05, 06:40 PM
I’m really struggling here, if A = 50 and wt = 5000

If I want to know freq should I take the sin of 50(0.7666) and then multiply that by 5000


I have 10 problems I need to lean how to use this equation.

LeBrad
Jun22-05, 08:30 PM
Sine is really important and something you should know well. If you have a graphing calculator, I would suggest plotting a bunch of A\sin(\omega t+\phi)+C equations to see how the graph changes as the parameters change.

Sine itself can never get bigger than 1, and the things inside the sin can never change the height of the graph. \omega and \phi, which go inside sin, only change the spacing and position with respect to the t axis. \omega is the frequency, or how frequently the curve goes from top to bottom. \phi just shifts it left and right on the time axis.

Since things inside sin don't change the height, that means only A and C can affect the position on the y axis. Since plain sin has a maximum value of 1, the maximum of A*sin will be whatver A is. Then if you add a C term, that just shifts the whole thing up or down on the y axis.

The frequency is \omega itself, and the amplitude is A itself. There's no need to take the sin of anything or multimply anything. You're just identifying parameters in the equation.

celect
Jun22-05, 08:49 PM
So my freq = 5000Hz
and my Amplitude = 50V.

willib
Jun22-05, 09:09 PM
as LeBrad and Delta said in your equation Vs = A*sin({\omega}t }) A=50 and \omega= 5000 ..
Maybe you are confused between Evaluating the equation and identifying the parameters ..
to evaluate the equation ,plug in T=0 or any value for t
So my freq = 5000Hzno \omega= 2Pi f
so your frequency in Hz 5000/2Pi

celect
Jun22-05, 09:42 PM
So are you stating I should have as an answer 5000/2 pi
the freq = 2500 pi Hz

willib
Jun22-05, 09:50 PM
So are you stating I should have as an answer 5000/2 pi
the freq = 2500 pi Hz
no i mean you should get 2500/pi Hz
approx 795 Hz..

celect
Jun22-05, 09:56 PM
Ok, I'm checking myself with text that has answers in back for just odd numbers.
the only answer they give is 2500/pi Hz
but the true answer is to go another step and divide the 2500 by pi.
ok
thanks.

123456
Jul16-07, 08:54 AM
Sir

I want to know the frequency of the sound using the hexadecimal value of sound.can u please tell me the formula for that.

berkeman
Jul16-07, 02:53 PM
Sir

I want to know the frequency of the sound using the hexadecimal value of sound.can u please tell me the formula for that.

Why would you want to convert the decimal frequency of sound into a hex number? What is the context of your question? Do you maybe mean convert between Hz (cycles per second) and Radians per second?

xez
Jul16-07, 03:22 PM
Hexadecimal is just base-16 using digits
0123456789abcdef
corresponding to decimal values 0-16.
Use a conversion calculator to get the decimal value,
or calculate it digit by digit as the sum of h * 16^n where
h is your hex digit in that place, and n increases from 0
on the right up to however many total hex digits you have.

As to the frequency that corresponds, that cannot be said
using only the information you've provided since generally
a hexadecimal number will correspond to some divisor value relative to some reference clock frequency that is
specific to a given digital system...

berkeman
Jul16-07, 03:25 PM
Hexadecimal is just base-16 using digits
0123456789abcdef
corresponding to decimal values 0-16.

Small typo -- 0x0 to 0xF corresponds to decimal 0-15. :biggrin: