﻿ MotionDesigner Reference & User Interface > Motion Laws > Flexible-Polynomial Motion-Law > Throw: Rapid-Return 1: Finite-Jerk @ Start/End/Mid-Point Motion-Law

# Throw: Rapid-Return 1: Finite-Jerk @ Start/End/Mid-Point Motion-Law

### Throw: Rapid-Return Finite Jerk

It is continuous in Position, Velocity and Acceleration.

We construct the Throw Motion-Law with two Flexible Polynomial segments.

Usually, the segments have an equal period, but this is not necessary.

Continuity at the Mid-Point

At the mid-point, the Position is at its maximum and the Velocity is zero.

At the mid-point, Acceleration is finite and negative.

At the mid-point, Jerk is discontinuous and unspecified

Position, Velocity, Acceleration, are Continuous.

Acceleration is unspecified at its mid-Point.

Jerk is discontinuous and unspecified

The Throw is Quick-Return because it has a large, negative acceleration at its maximum displacement.

#### Two Segment 'Rapid-Return Motion 1 Start

Position = 0

Zero Velocity

Zero Acceleration

Unspecified Jerk

Mid-Point

Position = 1

Zero Velocity

Match but Unspecified Acceleration

Unspecified Jerk

End

Position 2 = 0

Zero Velocity

Zero Acceleration

Unspecified Jerk