Galileo demonstrated that all objects will fall at the same rate (with the same acceleration) regardless of their weight. Downhill Racer demonstrates that not all round objects roll at the same rate, even if their weights are identical. The rate of acceleration of a rolling object (angular acceleration) depends not only on its mass, but on how that mass is distributed. This exhibit allows visitors to try rings, disks, edge and center-weighted disks on a smooth, gentle slope.