Answer:
A. 50 Hz
B. 2 m/s
Step-by-step explanation:
We'll begin by converting 20 ms to s. This can be obtained as follow:
1000 ms = 1 s
Therefore,
20 ms = 20 ms × 1 s / 1000 ms
20 ms = 0.02 s
Next, we shall convert the value of the wavelength (i.e 4cm) to m. This can be obtained as follow:
100 cm = 1 m
Therefore,
4 cm = 4 cm × 1 m / 100 cm
4 cm = 0.04 m
A. Determination of the frequency.
Period (T) = 0.02 s
Frequency (f) =?
f = 1 / T
f = 1 / 0.02
f = 50 Hz
Therefore, the frequency of the wave is 50 Hz
B. Determination of the velocity.
Wavelength (λ) = 0.04 m
Frequency (f) = 50 Hz
Velocity (v) =?
v = λf
V = 0.04 × 50
v = 2 m/s
Therefore, the velocity of the wave is 2 m/s