Testing Your Rover
The rover is "wound up" by rolling it across a surface or by holding it horizontally in both hands and rotating it. As the can rotates, both ends of the rubber band twists, while the ballast canister, holding the center of the rubber band, remains hanging in the middle of the can, and does not turn as the can is rotated. Energy from the person turning the can is stored (potential energy) in the rubber band as it twists.
A rover with stored energy is set in motion when it is set down on the floor. At the moment of release, the twisted rubber band exerts an equal force on the ballast canister and the can. The ballast becomes the anchor that enables the rubber band to exert force n the can. Potential energy is converted to kinetic energy as the rubber band untwists and the can rolls. The can will roll until the rubber band is unwound, or no longer has enough energy to moe the can.
A ballast is a heavy object used to stabilize something. In the rover, the weight suspended from the rubber band serves as a ballast: it holds the middle of the rubber band stable while the can rotates around it.
A rover with stored energy is set in motion when it is set down on the floor. At the moment of release, the twisted rubber band exerts an equal force on the ballast canister and the can. The ballast becomes the anchor that enables the rubber band to exert force n the can. Potential energy is converted to kinetic energy as the rubber band untwists and the can rolls. The can will roll until the rubber band is unwound, or no longer has enough energy to moe the can.
A ballast is a heavy object used to stabilize something. In the rover, the weight suspended from the rubber band serves as a ballast: it holds the middle of the rubber band stable while the can rotates around it.