Answer
The amplitude of the two traveling waves that interfere to produce this wave is $~~0.020~m$
Work Step by Step
$y(x,t) = 0.040~sin(5\pi x)~cos(40 \pi t)$
We can write a general equation for the resultant wave:
$y(x,t) = 2y_m~sin(k x)~cos(\omega t)$
We can find the amplitude $y_m$ of the two traveling waves that interfere to produce this wave:
$2y_m = 0.040~m$
$y_m = \frac{0.040~m}{2}$
$y_m = 0.020~m$
The amplitude of the two traveling waves that interfere to produce this wave is $~~0.020~m$
