The period of a wave is found to be 50 seconds. What is the frequency of the wave?

The answer is this.

1/50 = 0.02 Hz

If you remember this one rule, then you can always convert

in either direction between frequency and period.

(Frequency) times (Period) = 1.

So Frequency = 1 / period

= 1 / (50 seconds)

= (1/50) per second

= 0.02 per second

= 0.02 Hertz