The video opens with a cacophony of bangs and bonks, as the unseen officer loses a great battle. Suddenly, he toboggans into frame, turtle-style legs first, face-down whipping along the outer rim of the slide before he spills from its wide metal maw onto the ground.

After the clip of a Boston police officer catapulting out of a childrens slide at the recently renovated City Hall Plaza playground went viral , many wondered how the officer reached such an alarming speed. (The officer sustained and recovered from a minor head injury.) Boston Mayor Michelle Wu promised to make sure theres more signage that this is for children or something.

Out of a shared concern for playground safety, HuffPost asked a physicist why the officer was going so fast and how others could avoid his misadventures.

Normal people, when they go down a slide, theyre fine, said Rhett Allain, an associate professor of physics at Southeastern Louisiana University and the author of The Physics of Going Fastbut Not Too Faston a Giant Slide, for Wired . I would guess it has to be something about the clothes hes wearing.

All other things being equal, a child and an adult ought to go down a slide at the same speed. Yes, the earths gravitational pull increases with an objects mass but objects with more mass also accelerate more slowly, and the two factors perfectly cancel each other out, Allain said. Its the reason why, if you drop a golf ball and a bowling ball from the same height, theyll hit the ground at the same time.

The major difference-maker is friction.

Friction depends on the two surfaces interacting, so if you have a metal slide and its in contact with skin or cotton clothes you have a certain coefficient of friction, Allain said. And if you change the material, maybe to something stiff, it could make it a lot slipperier.

If the officer gave himself a little push at the top of the slide, he added, it could contribute but not altogether explain his velocity.

The video shows the officer dressed in a neon vest and a typical officers uniform. A slight sheen on the pants suggests the fabric is synthetic or tightly woven and slippery.

A public information officer for the Boston Police Department did not immediately respond to HuffPosts request for comment on the material used to make officers uniforms.