The Physics of Standing on Stilts

Back to day 1 in Canada...While my cousin and cousin-in-law were doing some last minute Christmas shopping (predictably, they are both females), we spotted one of the characters from the Cirque du Soleil cast who were set to perform on Christmas Day.

This seemingly simple trick of towering over average human beings involves a lot of physics concepts that we've already learned in the past. Of course the most obvious concept involves Newton's Forces. The performer exerts a force on the stilts she uses to increase her height and at the same time the stilts exert an equal but opposite force. These two forces must be equal to each other as the object does not move in the y direction. Furthermore, the forces the performer exerts on the two stilts (for two legs) must be equal to each other; otherwise, she would lean on one side and increase the chance of falling down.

Moreover, this situation also involves the concept of the center of gravity or the center of mass. As in my previous blog about J.K. Rowling's Tales of Beetle the Bard, the performer would be able to balance more easily if she does not bring her legs / stilts too close to each other when standing or moving around because in order to maintain one's balance, the center of mass / center of gravity must be at its lowest point and this is achieved when the weight is more spread out within the object. This is why when humans try to balance on tight rope / ledges with really minuscule width values, the arms are spread out in an attempt to get our center of mass at its lowest point and prevent our fall.