Frequency and Period

A typical hard disk in a computer spins at 7200 rpm.

What is the frequency in rev/s?

1 min = 60 seconds

7200 / 60 =

120 rev/s

What is the period in seconds?

period = 1/7200

= 0.000138 minute

= 0.0083 second

= 8.3 x 10^-3