| A11-1 | Rolling up hill. |
| Purpose: | To demonstrate center of mass. |
| Description: | A "V"-shaped rail is set so that its open end is higher than its closed end. A double cone put at the closed end will roll uphill to the open end. The axis of the cone actually descends as the two rails diverge. |
| References: | B1-06. |
| Equipment: | double cone and V-shaped rail. |