How to Calculate Rotational Latency

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Rotational latency is the amount of time required for an object, at some angular velocity, to achieve an entire rotation throughout its path. This calculation is used extensively in real-world applications. For example, the speedometer in a car is based on the size of the tires installed on the car. Changing the size of the tires changes the rotational latency and therefore induces error into the speedometer. This calculation is also used in the field of informatics to determine the maximum read time from a hard drive, as the data is stored on disks that rotate in angular fashion.

Convert the angular velocity into a fractional form. For example, given a hard drive velocity of 7,200 rotations per minute, the fraction yielded would be 7,200 rotations / 1 minute.

Convert the value of minute in the denominator to seconds. Continuing the example, 7,200 rotations / 1 minute converted is equal to 7,200 rotations / 60 seconds.

Remove the unit of "rotations" from the fraction and invert the numerical values. The denominator will still be seconds. Continuing from above, 7,200 rotations / 60 seconds yields 60 / 7,200 seconds.

Perform the indicated division. In conclusion, 60 / 7,200 seconds returns the value of approximately 0.00833 seconds or 8.3 milliseconds. This final result is the rotational latency.