Two forces act on the helicopter. The first is gravity, which pulls the helicopter toward the ground. The second is air resistance, which pushes up on the helicopter as it falls. The faster the helicopter is falling, the more air resistance pushes on the helicopter.
As the helicopter falls, it accelerates until it reaches terminal velocity (the speed at which the force of air resistance equals the force of gravity). The forces are then balanced, and the helicopter experiences no more accelerations (increase in speed), keeping a constant velocity (speed) for the rest of the fall.
Mess Kits are single-serving experiments that allow kids to explore scientific concepts at their own pace. Visitors are encouraged to complete as many as they want! See all Mess Kits.