What units are acceleration measured in?

Acceleration is a measure of how quickly the velocity of an object is changing over time. The standard unit for measuring acceleration in the metric system is meters per second squared (m/s²), which is a measure of how many meters per second the velocity increases for every second that passes.

The choice indicating millimeters per second squared (mm/s²) or g's provides specific contexts in which acceleration can be measured. "g's" refers to the acceleration due to gravity, which is approximately 9.81 m/s², commonly used in both scientific and engineering contexts to express acceleration relative to the gravitational force. The designation of "rms" indicates a root mean square value, which is used when dealing with vibrational data, providing a way to quantify varying accelerations in a consistent manner.

While other options might mention forms of acceleration, they do not accurately encapsulate the standard measurement units used in vibration analysis or general physics for acceleration. The correct choice emphasizes widely accepted units used in both metric and imperial systems, aligning with principles and practices relevant to vibration analysis.