Answer:
λ = 0.28m
Step-by-step explanation:
Equation used is v = λf, where v is velocity, λ is wavelength, and f is frequency
We need to find wavelength so rearrange the equation in term of wavelength.
v = λf
λ = f/v
We know that period is the inverse of frequency (f = 1/T), so lets substitute that into our equation
λ = f/v
λ = (1/T)/v
Plug in your the given values given in the question.
We're given v=12m/s and T=3sec
λ = (1/T)/v
λ = (1/3)/12
λ = 1/36 = 0.2777777 = 0.28m