Hi again, here to talk a little about the physics behind roller coasters!

Something you might not know, or maybe you knew it on some level but never really thought about it - roller coasters aren't propelled along the ups and downs of the ride - they don't use an engine. They're only pulled to the top of the first hill; in order to get through the rest, the carts have to have enough forward momentum to get over the hills and/or through the loops.

It all depends on the conversion of kinetic energy to potential energy and vice versa. Potential energy, given by the equation Pe = mgh, is at a maximum when the roller coaster is at the top of a hill, since it's height is the greatest. As it starts traveling down the hill, it's Pe is transfered into kinetic energy (Ke), given by (1/2)mv^2. Kinetic energy is at its maximum at the bottom of the hill because this is where it has its highest velocity, high enough to get the roller coaster up and over the next hill. In turn, then, the roller coaster's hills must be high enough to allow for a fast enough velocity when the cart reaches the bottom in order to get it over the next hill. Of course, it would make sense then that when Ke is at its maximum, Pe is at its minimum and vice versa. Crazy, right? Physics is bomb.

You might be wondering how the ride runs smoothly without an engine on the cart, and how it stops when you get to the end (or rather, the beginning) of the track. Well, the wheels offer a lot of help - there are three sets of them. Running wheels guide the coaster on the track, friction wheels control lateral motion (movement to either side of the track), and a final set of wheels keeps the coaster on the track even if it's inverted. Compressed air brakes are what stop the car as the ride ends.

So there's a bit about the physics behind roller coasters! If this blog post freaked you out a little when you realized roller coasters don't actually have an engine and we're basically on our own in the cart from beginning to end, don't worry. Riding roller coasters is actually more safe than most regular activities, like playing sports or riding your bike. The engineers that design them and the Amusement park owners who hire these engineers make sure of that - otherwise they'd be in for some pretty serious lawsuits.

Thanks for reading! Until next time,