The *scalar space* of a motion is the arc length along the curve it traces out. The *scalar time* of a motion is the travel time along the route it traces out.

The *time rate* is “The rate at which something takes place over time.” The *space rate* is the rate at which something takes time over a route.

A quantity at an instant of time is *instantaneous*. A quantity at a point in space is *punctaneous*, from Latin *punct*(us) + (instant)*aneous*.

*Speed* is the time rate of motion, the scalar space per unit of scalar time. The speed at an instant of time is called the *instantaneous* speed, which equals the differential scalar space per differential scalar time or the magnitude of the instantaneous velocity.

*Pace* is the space rate of motion, the scalar time per unit of scalar space. The pace at a point of space is called the *punctaneous* pace, which equals the differential scalar space per differential scalar time or the magnitude of the punctaneous legerity. A gradient is the space rate of change of a function or scalar field.

*Displacement* is the directed distance or vector difference between two points in three-dimensional space. *Distimement* is the directed duration or vector difference between two instants in three-dimensional time.

*Velocity* is the time rate of change of distimement, which consists of the speed and direction of motion. The average velocity is the displacement per scalar time of motion. The velocity at an instant of time is called the *instantaneous* velocity, and is the differential displacement per differential scalar time. The instantaneous velocity equals the time rate of change of the displacement.

*Legerity *is the space rate of change of distimement, which consists of the pace and direction of motion. Legerity is the rate of progress on a trajectory or path. The average legerity is the distimement per scalar space of motion. The legerity at a point of space is called the *punctaneous* legerity, and is the differential distimement per differential scalar space. Cf. velocity.

*Acceleration* is the time rate of change of velocity. *Expedience* is the space rate of change of legerity.

The first moment of mass is mass times distance. The *momentum* is the time rate of change of the first moment of mass. The first moment of vass is vass times duration. The space rate of change of the first moment of vass is the *fulmentum*, from Latin for prop, support.

*Power* is the time rate of change of energy. *Force* is the space rate of change of energy.