“Would you consider Tony Hawk a physicist?”

“I would consider Tony Hawk a physicist. If nothing else, he’s an intuitive scientist, right?”

It looks like magic. When skateboarders launch off the lip of a vert ramp to fly into flips and spins, it appears they’re defying gravity. In fact, these athletes are exploiting the laws of physics.

On June 14-15, the legend Tony Hawk hosted the 2024 Vert Alert contest at the Jon M. Huntsman Center on the U campus where he and the world’s best vert skaters showed their stuff. The display inspired Kevin Davenport, assistant lecture professor in the Department of Physics & Astronomy, to break down the physics that allows vert skaters to huck themselves into the stratosphere. Watch the video below to learn why he calls Tony Hawk an intuitive scientist!

Conservation of energy

“The goal is to get as much air as possible so you’re in the air long enough to do tricks, right? You want to be able to spin and do whatever you want to be able to do. The ruling principle of all of this skateboarding and just motion in general really is the conservation of energy. There is some fixed amount of energy that we have in a system. There’s what’s called potential energy, and then there’s the energy of actually moving kinetic energy. So on a skateboard ramp, you start at the top and referenced to the bottom of the ramp, you have some amount of potential, and as soon as you step off and start falling, you are converting that into kinetic energy.”

Conservation of angular momentum

“The only way that a skateboarder can get air is that they have to, along the way, they have to add energy to the system. They have to do something to adjust their speed. It’s called pumping. In skateboarding, if you watch how skateboarders like their body position, they’ll go into that curve and they’re kind of squatted down a little bit, and as they go up, they’ll stand up and move their center of mass towards the center of the circle. And so what this is exploiting in physics is the conservation of angular momentum.

You will go faster when you come out of that curve, and every single time they’ll land and they’ll squat down and stand up and squat down and stand up. And every single time they’re doing that, they’re increasing their velocity a little bit more and more and more, and they can get higher and higher and higher each time.”

The fathers of the vert ramp were…Galileo, Isaac Newton and Johann Bernoulli?

“The shape of a vert ramp is really important. It all stems from a really important historical question that the greatest mathematical minds really thought about—Isaac Newton, Johann Bernoulli and Galileo. What is the path that will get you from A to B in the least amount of time? They used their newly invented mathematics of calculus to answer this question and it turns out the most efficient shape is this thing with a fantastic name. It’s called a Brachistochrone curve.

But part of doing vert skating is you don’t want to get from point A to point B in the least amount of time. You want to get as fast as you can in the least amount of time, and by far, the path that you will take through space to get you as fast as possible, is just to drop an object, and that’s how a vert ramp is designed. You literally stand at the top and you fall into this curve, and then you move on the flat portion.”

• Lisa Potter Research communications specialist, University of Utah Communications
  949-533-7899 lisa.potter@utah.edu