F ( t ) {\displaystyle \mathbf {F} (t)\;} is linear force - or thrust - applied upon the center of mass of the body, changing with time. v ( t ) {\displaystyle \mathbf {v} (t)\;} is velocity of the center of mass of the body, changing with time. τ ( t ) {\displaystyle \mathbf {\tau } (t)\;} is torque applied upon the center of mass of the body, changing with time. ω ( t ) {\displaystyle \mathbf {\omega } (t)\;} is angular velocity of the center of mass of the body, changing with time.