Frequency Converter
Hz, RPM, Rad/s & Time Period
What is Frequency?
Frequency measures how often an event repeats itself over a specific time. In physics and engineering, the standard unit is Hertz (Hz), which simply means "cycles per second."
- 1 Hz: Happens once every second (e.g., a ticking clock).
- 60 Hz: Happens 60 times per second (e.g., standard AC electricity).
- 100 MHz: Happens 100 million times per second (e.g., FM Radio).
The Relationship with Time (Period)
Frequency and Time are inverse cousins. The "Period" (T) is the time it takes to complete one cycle.
Formula: f = 1 ÷ T
If you know the time, you know the frequency:
- If a wave takes 0.5 seconds to repeat, the frequency is 2 Hz.
- If a wave takes 0.001 seconds (1 ms), the frequency is 1000 Hz (1 kHz).
RPM: The Mechanic's Unit
While physicists use Hz, mechanics and car enthusiasts use RPM (Revolutions Per Minute). It measures rotational speed.
The Calculation:
Since there are 60 seconds in a minute:
1 Hz = 60 RPM.
If your car engine is spinning at 3,000 RPM, that means the crankshaft is rotating 50 times every single second (50 Hz).
Since there are 60 seconds in a minute:
1 Hz = 60 RPM.
If your car engine is spinning at 3,000 RPM, that means the crankshaft is rotating 50 times every single second (50 Hz).
Audio Frequency Spectrum
Sound is just a vibration (frequency) traveling through air. The human ear can detect a specific range of these vibrations.
| Range | Frequency | Description |
|---|---|---|
| Infrasound | < 20 Hz | Felt as vibration (Earthquakes, Elephants). |
| Bass | 20 Hz - 250 Hz | Deep sounds, drum beats. |
| Midrange | 250 Hz - 4 kHz | Human voice range. |
| Treble | 4 kHz - 20 kHz | Cymbals, bird chirps. |
| Ultrasound | > 20 kHz | Dog whistles, Medical imaging. |