Standing waves and harmonic waves

[glasshut137]

[SOLVED] standing waves

Homework Statement

A standing wave is a superposition of two harmonic waves described by
y1= Asin(kx+wt) and
y2= A sin(kx-wt),

where A=3.31594 cm, k=10.0531 m-1, and w=18.2212 s-1.

Determine the smallest positive value of x correspoding to a node.

So i added the two waves together and got y=2Asin(kx)cos(wt). I set y=0 and tried solving for x but i just got zero which was incorrect. Can someone help me solve these types of problems. Thanks.

 

[olgranpappy]

there are a lot of x values for which

0=2Asin(kx)

is true... x=0 is one of them.

to find the other zeros you have to know the zeros of the sin function... i.e., 0,pi,2pi,3pi, etc

so set kx equal to the smallest *nonzero* value listed above to find the node you want.