Answer:
The distance between two successive crests of a wave is one way to define its wavelength, so
λ
=
1.15
m
.
The frequency of a wave is the number of waves passing a given point per second, so
f
=
20
16.2
=
1.23
Hz
.
The speed of a wave is given* as
v
=
λ
f
, so here
v
=
1.15
⋅
1.23
=
1.42
m/s
~~~~
*This is because the wavelength is the "distance per wave" and the frequency is the "number of waves per second," so multiplying the two gives "distance per second." This can be verified with dimensional analysis:
meters
wave
×
waves
second
=
meters
second
