Question

4th answer please argent
and 6th all please

Answer 1

4th ANSWER:
Velocity ,V=4m/s
Time period ,T=0.4
frequency,ν=1/T  = 1/0.4=2.5
V= ν*λ                                          
ν=nue(frequency); λ=lambda(wavelenght)
λ=V/ν
   =4/2.5
   =1.6m
Hence the wavelenght is 1.6m.

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