# You Can Jump Like a Superhero — If You Are In an Accelerating Frame

You see a bunch of awesome (and sometimes weird) stuff online. In this case, it appears to be an attendant on a carnival ride doing a seemingly impossible jump. Check it out.

This appears to be on a ride that both rotates AND moves up and down. With a little bit of searching, it seems like it’s called TAGADA in Korea and the guy does a loose back layout while the thing rotates. Since the video was recorded by someone riding on the edge and the camera bobbles around, I made a frame corrected view.

Newton’s Laws in Accelerated Reference Frames

If we want to figure out what’s going on here, we need to think about Newton’s 2nd Law and how it works in different reference frames. First, we have the 2nd law. This gives a relationship between the net force on an object and that object’s acceleration.

It might seem too simple, but let’s use Newton’s 2nd law for a human standing in a stationary elevator. There’s really just two forces acting on the person: the downward gravitational force and the upward force from the floor.

Nothing crazy there. But now imagine that the elevator is accelerating upwards (starting to speed up as it moves up). I mean, surely you have been in an elevator, right? If not, you need to find one of those things and get in it. When you push the “up” button, the elevator accelerates up to it’s traveling speed. During that time, something sort of magic happens — you “feel” heavier. It’s weird and awesome at the same time.

But what’s going on during that motion? Are you actually heavier? Did the gravitational force from the Earth INCREASE because you pushed that “up” button? Of…

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Physics faculty, science blogger of all things geek. Technical Consultant for CBS MacGyver and MythBusters. WIRED blogger.