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In physics, rotatum is the derivative of torque with respect to time. Expressed as an equation, rotatum Ρ is:

where τ is torque and is the derivative with respect to time .

The term rotatum is not universally recognized but is commonly used. This word is derived from the Latin word rotātus meaning to rotate.[citation needed] The units of rotatum are force times distance per time, or equivalently, mass times length squared per time cubed; in the SI unit system this is kilogram metre squared per second cubed (kg·m2/s3), or Newtons times meter per second (N·m/s).

Relation to other physical quantities

Newton's second law for angular motion says that:

where L is angular momentum, so if we combine the above two equations:

where is moment of Inertia and is angular velocity. If the moment of inertia is not changing over time (i.e. it is constant), then:

which can also be written as:

where is angular jerk.