Data:
ΔS = 60cm
Δt = 3s
Vm = ?
Vm = ΔS/Δt
[tex]Vm = \frac{60}{3} [/tex]
[tex]Vm = 20cm/s[/tex]
We have:
Vm = v
ΔS = λ
Δt = T
[tex]v = \frac{\lambda}{T} [/tex]
[tex]20 = \frac{\lambda}{4} [/tex]
[tex]\lambda = 20*4[/tex]
[tex]\lambda = 80cm[/tex]
Soon:
[tex]v = \lambda*f[/tex]
[tex]20 = 80*f[/tex]
[tex]80f = 20[/tex]
[tex]f = \frac{20}{80} simplify( \frac{\div20}{\div20} )= \frac{1}{4} [/tex]
[tex]\boxed{f = 0,25Hz}[/tex]
