ANSWER:
STEP-BY-STEP EXPLANATION:
We calculate in each case for the first part:
Given:
Wavelenth (λ) = 3405
Period (T) = 620
[tex]\begin{gathered} f=\frac{1}{T}=\frac{1}{620} \\ f=0.0016\text{ Hz} \\ \\ v=f\cdot\:\lambda=0.0016\cdot3405 \\ v=5.4\text{ m/s} \\ \\ E=\frac{1}{\lambda}=\frac{1}{3405} \\ E=0.00029\text{ J} \end{gathered}[/tex]
Now for the second part:
Given:
Wavelenth (λ) = 15.2
Velocity (v) = 25.3
[tex]\begin{gathered} f=\frac{v}{\lambda}=\frac{25.3}{15.2} \\ f=1.7\text{ Hz} \\ \\ T=\frac{1}{f}=\frac{1}{1.7} \\ T=0.59\text{ s} \\ \\ E=\frac{1}{\lambda}=\frac{1}{15.2} \\ W=0.066 \end{gathered}[/tex]
