# physics (please help)

posted by
**susan** on
.

Let f be the frequency, v wav the speed, and T the period of a sinusoidal traveling wave. The correct relationship is:

a)f=1/T

b)f=vwav + T

c)f=vwavT

d)f=vwav/T

e)f=T/vwav

My thoughts:

Since frequency is equal to T=1/f so f=1/T. Vwav is connected to f by the equation v=lambda* frequency. so f=v/lambda. I have to connect the to f= equations inorder to get the relationship. I chose d because it seemed to combine the both.

For a transverse wave on a string the strong displacement is described as y(x,t)=f(x-at), where f is a given function and a is a positive constant. Which of the following does not necessarily follow this statement?

a)the shape of the string at time t=o is given by f(x)

b) the shape of the waveform does not change as it moves along a string

c) the waveform moves in the positive x direction

d) the speed of the waveform is a

e) the speed of the waveform is x/t

thoughts:

When I looked at the function equation y(x,t)=f(x-at). I thought to compare it with y(x,t)=f(kx-wt). I know that f can stand for Sin or Cos. I thought a can not be equal to the speed of the wave since v=w/k would equal it. So I chose d.

Thank you for your help.

For the first one, I believe the answer is a, as I learned in Honors Precalculus that frequency and period are indirectly related. That is, f=1/p and p=1/f. The equation is the same in a, though the variables are different. I could be wrong though.

correct, the other answers are silly. a is the correct answer.

but it says that you have to connect all three.v,f, and T. I thought of that to f=1/T.

Can you help me with the second?

I wish I could, but I haven't taken Physics. Sorry!