Waves traveling through a string

[j88k]

Homework Statement

A string of length L vibrates at its fundamental frequency. The amplitude at a point (1/4) L from one end is 6.00 .

What is the amplitude of each of the traveling waves that form this standing wave?

Homework Equations

none

The Attempt at a Solution

I absolutely don't know where to start. Have to submit it as soon as possible and I'm running out of options.
Please help :s

 

[rl.bhat]

In the standing wave, the displacement of the particles of the string is given by
y(x,t) = A*sin(kx)*cos(wt). For all the particles cos(wt) remains constant. When kx = 0, the point is node. When kx = pi/2, the point is anti node, which is at the middle of the string. At L/4, kx must be pi/4. Now find A.

 

[j88k]

In the standing wave, the displacement of the particles of the string is given by
y(x,t) = A*sin(kx)*cos(wt). For all the particles cos(wt) remains constant. When kx = 0, the point is node. When kx = pi/2, the point is anti node, which is at the middle of the string. At L/4, kx must be pi/4. Now find A.

what goes for y(x,t) and cos(wt) then?

 

[j88k]

anyone ?

 

[rl.bhat]

what goes for y(x,t) and cos(wt) then?
y(x,t) is the vertical amplitude if the vibrating particle and (wt) is the angular velocity of the particle which is same for all particles.

 

[j88k]

sorry for being extremely shallow, but what it (wt) ?

I looked everywhere and I can't seem to find the constant.

 

[rl.bhat]

w = 2*pi/T where T is the time for one oscillation. It is constant for all particles. And t is the time.