Waves Lab 2 Section II
Consider the general case of two waves travelling in the same direction
y1(x,t) = ym sin(k1 x - ?1 t )
y2(x,t) = ym sin(k2 x - ?2 t )
y(x,t) = y1(x,t)+ y2(x,t)
sin A + sin B = 2 sin[(A+B)/2] cos[(A-B)/2]
y(x,t)=2ym cos[(k1- k2)x/2 -(?1- ?2)t/2] x sin [(k1+ k2)x/2 -(?1+ ?2)t/2]
y(x,t)={2ym cos [(?k/2)x -(??/2)t]} x sin[(k1+ k2)x/2 -(?1+ ?2)t/2]