Question

you want to describe the harmonic motion of a swing. You find out that it take 2 seconds for the swing to complete one cycle. What is the swing's period and frequency?

Answer 1

The 2 seconds that it takes tocomplete one full cycle
is the period of the motion ... 2 seconds .

The frequency is the reciprocal of the period . . . 1 / 2 seconds  = 0.5 Hz.