| DCS # | DEMONSTRATION | REFERENCE | ABSTRACT |
|---|
| 1J20.00 | Stable, Unstab., and Neut. Equi | | |
| 1J20.10 | bowling ball stability | PIRA 500 | |
| 1J20.10 | bowling ball stability | 1J20.10 | A bowling ball is placed in, on, and along side a large plexiglass hemisphere. |
| 1J20.11 | balance the cone | PIRA 1000 | |
| 1J20.11 | balance the cone | 1J20.11 | |
| 1J20.11 | balance the cone | Mq-2 | A cone can show stable, unstable, and neutral equilibrium; a sphere shows only neutral equilibrium. |
| 1J20.11 | balance the cone | M-39 | A large cone shows stable, unstable, and neutral equilibrium. |
| 1J20.11 | stability | Disc 03-19 | Balance a cone, show a block is stable and a sphere is neutral. |
| 1J20.12 | wood block stability | PIRA 1000 | |
| 1J20.12 | wood block stability | 1J20.12 | A block and support have marks that show whether the center of gravity has moved up or down when the block is displaced. |
| 1J20.15 | block on the cylinder | PIRA 1000 | |
| 1J20.15 | block on the cylinder | 1J20.15 | A rectangular block of wood is placed on a cylinder first with the width less than the radius (stable) and then with the width greater (unstable). |
| 1J20.15 | block on the cylinder | AJP 51(7),636 | An "elementary" discussion of the oscillatory properties of the block on the cylinder. |
| 1J20.15 | block on the cylinder | Mq-1 | A thin block on a cylinder is stable, a thick one is not. |
| 1J20.16 | catenary surface | M-40 | A large block is always in stable equilibrium anywhere along this catenary surface. |
| 1J20.17 | block on curved surfaces | PIRA 1000 | |
| 1J20.17 | block on curved surfaces | 1J20.17 | A block is placed on a catenary surface, a circle, and a parabola. |
| 1J20.20 | fork, spoon, and match | PIRA 1000 | |
| 1J20.20 | fork, spoon, and match | 1J20.20 | Place a spoon and match in the tines of a fork and balance the assembly on the edge of a glass. |
| 1J20.20 | fork, spoon, and match | TPT 10(8),464 | Picture of the fork, spoon, and match balanced on the edge of a glass. |
| 1J20.20 | fork, spoon, and match | Mp-5 | Stick two forks and a match together and balance on a glass while pouring out the water. |
| 1J20.20 | fork, spoon, and match | 14-3.8 | Two forks and a match can be balanced on the edge of a glass while the water is poured out. |
| 1J20.25 | nine nails on one | PIRA 1000 | |
| 1J20.25 | nine nails on one | 1J20.25 | A technique to balance ten landscape spikes on the head of a single upright spike. |
| 1J20.30 | sky hook | PIRA 500 | |
| 1J20.30 | sky hook | TPT 14(8),499 | A complete solution to the hanging belt problem. |
| 1J20.30 | hanging belt | TPT 15(4),241 | Shows a "belt hook" for the hanging belt. |
| 1J20.32 | spoon on nose | PIRA 1000 | |
| 1J20.32 | spoon on nose | 1J20.32 | Hang a spoon on your nose. Most effective with giant food service spoons. |
| 1J20.35 | horse and rider | PIRA 1000 | |
| 1J20.35 | horse and rider | Mp-4 | A horse has an attached weight to lower the center of mass. |
| 1J20.35 | horse and rider | M-33 | Stable equilibrium of a center of gravity object. |
| 1J20.35 | horse and rider | M-18a.2 | A horse has a weight attached to lower the center of mass. |
| 1J20.40 | balancing man | M-36 | Stable equilibrium of a center of gravity object. |
| 1J20.40 | balancing man | M-38 | Stable equilibrium of a center of gravity object. |
| 1J20.45 | tightrope walking | PIRA 500 | |
| 1J20.45 | tightrope walking | AJP 50(5),471 | Design of a 10' long "low wire" and description of the physical feats possible. |
| 1J20.45 | tightrope walking | Mp-6 | A toy unicycle rider carrying a balancing pole travels along a string. |
| 1J20.45 | clown on rope | Disc 03-23 | A toy clown rides a unicycle on a wire. |
| 1J20.46 | tightrope walking model | PIRA 1000 | |
| 1J20.46 | tightrope walking model | 1J20.46 | A model of a tightrope walker shows the center of mass moves up with tipping. |
| 1J20.50 | balancing a stool | Mp-12 | Wires form a support at the center of gravity of a lab stool. |
| 1J20.50 | balancing a stool | 14-2.2 | Construct a stool so that wires crossed diagonally will intersect at the center of gravity. The stool can be oriented in any direction. |
| 1J20.51 | chair on a pedestal | PIRA 1000 | |
| 1J20.51 | chair on pedestal | Disc 03-22 | Hide heavy weights in the ends of a chair's legs so it will balance on a vertical rod placed under the seat. |
| 1J20.55 | broom stand | PIRA 1000 | |
| 1J20.55 | broom stand | Disc 04-19 | Spread the bristles and a straw broom will stand upright. |
| 1J20.60 | wine butler | PIRA 500 | |
| 1J20.60 | wine buttler | 1J20.60 | Stick the neck of a wine bottle through a hole in a slanted board and the whole thing stand up. |
| 1J20.65 | glass on coin, etc | TPT 14(1),39 | Pictures show the hanging belt, pin on the point of a needle, and a jar balanced on its edge. |