Sometimes the frequency is known and the period is the question: a fan spins at 4 Hz, and you want the time each revolution takes. f = 1/T works in both directions.
Start from the equation you know: f = 1/T.
Make T the subject: multiply both sides by T, then divide both sides by f.
That gives T = 1/f.
With f in hertz, T comes out in seconds; with T in seconds, f comes out in hertz.
The fan spins at 4 Hz. Calculate its period.
Write down the values:
f = 4 Hz, T = ?
Write down the equation:
T = 1/f
Substitute in the values, and calculate:
T = 1 / 4 = 0.25
The fan's period is 0.25 s.
A drone rotor has a period of 0.05 s. Calculate its frequency.
Write down the values:
T = 0.05 s, f = ?
Write down the equation:
f = 1/T
Substitute in the values, and calculate:
f = 1 / 0.05 = 20
The rotor's frequency is 20 Hz.
A pottery wheel spins at 2.0 Hz. Enter its period in s.
A hamster wheel has a period of 0.8 s. Enter its frequency in Hz.
A kitchen mixer whisk spins at 8.0 Hz. Enter its period in s.
A rotisserie spit has a period of 2.5 s. Enter its frequency in Hz.
A revolving sign turns with a period of 1.6 s. Enter its frequency in Hz.
A power drill's chuck spins at 50 Hz. Enter its period in s.
During a slow bench test, a drone propeller spins at 10 Hz. Enter its period in s.
A bench grinder wheel has a period of 0.04 s. Enter its frequency in Hz.
At the park, a small merry-go-round completes exactly one fifth of a revolution each second, a frequency of 0.2 Hz. Enter its period in s.