The document describes a procedure using an NXT robot to operate a carousel. Pressing the start button causes the attached wheels to reverse direction as the motor changes rotation. To prevent the wheel from reversing, modifications must be made to the motor or wheel attachment to ensure consistent rotation.

1. The Carousel
Procedure:
1. Press on the start button of the NXT robot.
2. Observe the motion of the wheels attached to the carousel as the motor
reverses direction.
Questions:
1. What happened to the wheel when the motor reverses direction? Why?
2. What must be done to prevent it from happening?