Physics Glossary Carousels are not considered "thrill machines" by any stretch of the imagination. Still, carousels are as reliant on the laws of motion as their more exciting cousins, the roller coasters. It's theoretically possible that, allowed to spin out of control, a carousel could gain enough speed so that the riders would be thrown off. Thankfully, runaway carousels are not the least bit common.

Are some horses moving faster than others?
With all of its beauty and seeming simplicity, the carousel is a delicate balance of motion and forces. All of the horses move through one complete circle in the same amount of time. The horses on the outside of the carousel have to cover more distance than the inside horses in the same amount of time. This means the horses on the outside have a faster linear speed than those at the hub.

What if they're galloping?
On some carousels, the horses go up and down in a galloping motion simulating what it might be like to ride a real horse. For these carousels, the ride designer had to approach the problem of movement around the central axis differently. In a normal carousel, each horse maintains a constant acceleration, radius, and tangential speed (speed tangent to the circular path of the carousel). If you add a gallop to some of the horses, you must consider the forces needed to change that horse's position upward or downward as it goes around the track. In designing with these forces in mind, you also need to take into account the mass of the horse and its rider.

How do you tell the lead horse on a carousel? Find out what to look for.


"Amusement Park Physics" is inspired by programs from The Mechanical Universe...and Beyond.