Answer:
a) Longest wavelength is: [tex]\lambda_{1}=2*0.75=1.5\: m[/tex]
b) The frequency associated with this longest wavelength is: [tex]f=86.7\: Hz[/tex]
Explanation:
a)
The wavelength equation of a standing wave is given by:
[tex]\lambda_{n}=\frac{2}{n}L[/tex]
Where:
We use n=1 to find the longest possible wavelength, so we will have:
[tex]\lambda_{1}=2L[/tex]
[tex]\lambda_{1}=2*0.75=1.5\: m[/tex]
b)
The speed of the wave is given by:
[tex]v=f\lambda[/tex]
So we just need to find the f (frequency).
[tex]f=\frac{v}{\lambda}[/tex]
[tex]f=\frac{130}{1.5}[/tex]
[tex]f=86.7\: Hz[/tex]
I hope it helps you!