Poo Cocktail Supreme
Yeah, this is one of Jackass's more disgusting and extreme kind of stunts. Poo Cocktail Supreme was a scene in the Movie Jackass 3D. If you have ever been to a local fair and seen or rode in the slingshot ride, just imagine doing that while strapped into a portapotty, being launched 80 feet in the air. It stinks, doesn't it. Cast member Steve O was the victim of this stunt or gag for this film. There's also a deleted scene from this film where Britney Spears is performing this same exact stunt. This stunt was based from a similar stunt pulled in the first episode of the TV show and was performed by Johnny Knoxville.



Physics
This stunt is similar to a slingshot ride, so I’m gonna explain the physics in the same way. The slingshot works much like bungee jumping. Both of these are dependent on the elasticity of the bungee cords to create a force. In bungee jumping, the elastic force decelerates and stops the jumper when that person nosedives to the ground. The slingshot ride works in the opposite sense. The elasticity of the cord overpowers gravity by pulling upward and accelerating. Thus, launching the rider in to the sky. The rider in this scenario was strapped into a porta potty that was latched to the ground. This causes the bungee cords to stretch when fastened to two elevated poles to boost the potential energy.

Then when the porta potty is launched into the sky, it converts all the potential energy of the bungee cords into the kinetic energy of the rider launching him into the air. Once the latch connecting to the porta potty and the group is released, the rider feels the maximum acceleration. Energy will be dissipated with every pass, as heat is created by the friction. The friction is created by the bungee cords moving through the air and inside the bungee cords. The forces of gravity caused by the bungee acceleration are the similar forces that affect astronauts. When just standing still, the human body experiences the force of Fg, as gravity pulls bodies to the center of Earth. When acceleration ends and the bungee cords stop pulling, the only force the rider experiences is free fall.