Figure 1 shows a gear system consisting of two gears, Gear X and Gear Y.
Gear X is mounted on a fixed axle and can rotate.
Gear Y is a straight vertical gear (a rack) that can move up and down.
Gear X has 80 teeth.
The distance between successive teeth on both gears is 2.5 mm.
Gear X completes one full revolution in a clockwise direction.
Which of these describes the motion of Gear Y?
80 mm80\text{ mm}80 mm up
80 mm80\text{ mm}80 mm down
200 mm200\text{ mm}200 mm up
200 mm200\text{ mm}200 mm down