ANSWER:
71.3°
STEP-BY-STEP EXPLANATION:
Given:
Wavelength (λ) = 2.5 m
Source separation (d) = 6.6 m
Nodal line number (n) = 3
We can calculate the angle using the following formula:
[tex]\sin\theta=\left(n-\frac{1}{2}\right)\frac{\lambda}{d}[/tex]We substitute each value and calculate the angle like this:
[tex]\begin{gathered} \sinθ=\left(3-\frac{1}{2}\right)\frac{2.5}{6.6} \\ \\ \sinθ=0.94696 \\ \\ θ=\sin^{-1}(0.94696) \\ \\ θ=71.3\degree \end{gathered}[/tex]The angle of the third nodal line. es 71.3°