Answer:
1.2 Hz
Explanation:
Frequency: This can be defined as the number of cycles completed in one seconds. The unit of frequency is Hertz (Hz)
From the question above,
f = N/t.................... Equation 1
Where f = frequency, N = number of wave or cycle completed by Johnny, t = time take to complete the waves.
Given: N = 12 waves, t = 10 s
Substitute into equation 1
f = 12/10
f = 1.2 Hz
