Answer:
0.091 m/s
Explanation:
Given in the question that,
wavelength of a wave = 7mm
frequency of a wave = 13 hertz
Formula to use
here f = frequency in hertz
v = velocity in m/s
λ = wavelength in m
1 mm = 1x10[tex]^{-3}[/tex]
7mm = 7x10[tex]^{-3}[/tex]
Plug values in the formula
13 = v / 7x10[tex]^{-3}[/tex]
v = 13(7x10^{-3})
v = 0.091 m/s