A pendulum takes 6.0 seconds to swing through 5 complete cycles. What is the period of the pendulum?

When you look at this, you might not be sure which way to divide ...

Should you divide 6 by 5 or 5 by 6?

Here's a case where you can use your units to decide.

The question wants to know the 'period'. That's a length of time,

so the answer needs to have units of time.

If you divide 'cycles' be 'time', you'll get 'cycles/second'.

That's Hz. It's frequency, not time.

If you divide 'time' by 'cycles', you'll get 'seconds/cycle'.

That's time, and it's exactly the definition of 'period'.

Period = (6 seconds) / (5 cycles)

= (6 / 5) seconds/cycle

= 1.2 seconds