﻿ MotionDesigner Reference & User Interface > Motion Laws / Cam-Laws for Segments > Throw Motion-Law > Throw Quick-Return: 2: Zero Jerk @ Start/End/Mid-Point

# Throw Quick-Return: 2: Zero Jerk @ Start/End/Mid-Point

### Throw: Quick-Return with Zero Jerk at its Start and End

#### The Throw Motion-Law

Unlike the other motion-laws, the Throw motion-law rises from its Start-Position to its maximum displacement, and then returns to its Start-Position.

Use two Flexible Polynomial segments to design the Throw motion-law. Usually, the two segments have equal durations, but it is not necessary.

#### Throw: Quick-Return 1 - Zero Jerk at Start and End.

Because you use two Flexible-Polynomial segments to design the Throw motion-law, you can enter different motion-values and motion-constraints at its start, its maximum displacement, and at its end.

All Throw motion-laws have zero velocity and acceleration at their start and end.

This Throw motion-law also has zero Jerk at its start and end.

This Throw has a Quick-Return because it has a negative acceleration at its maximum displacement - the transition from Rise to Return.

#### Throw: Quick-Return - Zero Jerk at its Start-and End.

THROW: Quick-Return Zero Jerk Start, Middle, End

Motion-Values of each motion-derivative

Start of rise segment 1 :

X =0

Position = 0

Velocity = 0

Acceleration = 0

Jerk = 0

Mid-Point :

X=180 (you can move the X-axis value of the mid-point)

Position = 1

Velocity = 0

Acceleration = Unspecified (Actual value = -40.0mm/s/s )

Jerk = 0

End of return Segment 2 :

X=360

Position 2 = 0

Velocity  = 0

Acceleration = 0

Jerk = 0