Two transfersal sinusoidal wave

[dado]

Homework Statement

Two transfersal sinusoidal wave of amplitude 0.5 cm and 8 cm wavelength traveling in opposite
directions along the wire. Wave speed in the wire is 1.2 m / s. Write the equation of these two transfersal wave equation and find the resultant wave. Draw the shape of wire at time t = 0, 1, 2, ... s.

Homework Equations

s=A+sin(wt-kx)

The Attempt at a Solution

I did this
s1= 0,5*sin(30*pi*t - (pi*x)/4)
s2= 0,5*sin(30*pi*t + (pi*x)/4 + phi)
phi is an angle.

Did I wrote those equations right or not?

 

[ehild]

It is correct except the mistype in the first equation (+ instead of *).

The question to draw the shape at integer t values is weird (why?).

 

[dado]

thanks. How to find resultant wave if I don't know "phi"?

 

[ehild]

I think the problem meant phi=0, it would have been given otherwise.

ehild