What is the phase difference between the motions of two points on the wave

[looi76]

[SOLVED] What is the phase difference between the motions of two points on the wave..

Homework Statement

The frequency of a certain wave is $$500Hz$$ and its speed is $$340ms^{-1}$$.What is the phase difference between the motions of two points on the wave $$0.17cm$$ apart?

Homework Equations

$$x = \frac{d\lambda}{a}$$

$$v = f\lambda$$

The Attempt at a Solution

$$f = 500Hz \ \ \ v = 340ms^{-1} \ \ \ a = 0.17 \times 10^{-2} cm$$

$$v = f\lambda$$

$$\lambda = \frac{v}{f} = \frac{340}{500} = 0.68m$$

What should I do next?

 

[Kurdt]

Two points 0.68cm apart will be out of phase by 360 degrees.

 

[Antenna Guy]

Two points 0.68cm apart will be out of phase by 360 degrees.

Two points $\lambda$ apart will be out of phase by 360 deg.

Regards,

Bill

 

[Kurdt]

In this case that is 0.68m. Damn I just realized I said cm, but you know what I mean. :tongue:

 

[looi76]

So, the answer is = 0.68m by 360° ?

 

[Gib Z]

No, I won't be. You know the phase difference between points 0.68m apart is 360°, the question asks the phase difference for 0.17m, which happens to be a quarter the quantity of which we do know the phase difference for. Just one more step =]

 

[Antenna Guy]

So, the answer is = 0.68m by 360° ?

Define the terms in your first relevant equation - one of those terms should be what you solve for to get the answer.

BTW - check what you wrote for "a" (cm?).

Regards,

Bill

 

[Kurdt]

So, the answer is = 0.68m by 360° ?

As GibZ alluded to, I was trying to coax you toward the right answer not just give you the answer outright (since that would be against forum policy).

 

[looi76]

$$0.68m = 360^o$$
$$0.17m = x$$

$$x = \frac{0.17 \times 360}{0.68}$$

$$x = 90^o$$

So, the phase difference is $$90^o$$ ?

 

[Kurdt]

Thats correct.