An electric razor in Europe completes 50 vibrations in 1 s. The frequency of these vibrations is
A) 50 Hz with a period of 1/50 s.
B) 1/50 Hz with a period of 50 s.
C) 50 Hz with a period of 50 s.
D) 1/50 Hz with a period of 1/50 s.
Question 2
A wave of 60 vibrations per second travels 30 m in 1 s. Its frequency is
A) 30 Hz.
B) 60 Hz.
C) more than 60 Hz.
D) none of the above