Answer
The amplitude of the resultant wave is $~~6.7~mm$
Work Step by Step
We can find the horizontal component of the resultant wave's amplitude:
$y_{mh}' = (y_{m1}) cos ~(0) + (y_{m2}) cos~(70^{\circ})$
$y_{mh}' = (3.0~mm) cos ~(0) + (5.0~mm) cos~(70^{\circ})$
$y_{mh}' = 4.71~mm$
We can find the vertical component of the resultant wave's amplitude:
$y_{mv}' = (y_{m1}) sin ~(0) + (y_{m2}) sin~(70^{\circ})$
$y_{mv}' = (3.0~mm) sin ~(0) + (5.0~mm) sin~(70^{\circ})$
$y_{mv}' = 4.70~mm$
We can find the amplitude of the resultant wave:
$y_m' = \sqrt{(4.71~mm)^2+(4.70~mm)^2}$
$y_m' = 6.7~mm$
The amplitude of the resultant wave is $~~6.7~mm$
