We love snow days in Wonderopolis! When the first snowflakes begin to fall just as we're going to bed, we wonder what the landscape will look like in the morning.

If we wake up to a blanket of white, we have one thing on our minds: sledding!

Do you have a sled? Or a toboggan? Maybe even a sleigh? What's the difference between these things anyway?

Whatever you call them, they all work in a similar way. Whether they have a smooth bottom or a small platform that sits on long, narrow runners, they travel by sliding across a low-friction surface, such as snow or ice.

For example, the blades of grass on a hill would normally not allow you to slide down very quickly because they help your body stay in contact with the ground. The blades of grass and the ground itself both create friction, which is a force that generates heat and tends to slow objects down.

Try rubbing your palms together, pushing slightly as you move your hands. The resistance you feel is friction. Friction slows an object down.

If those blades of grass and the ground get coated with ice or snow, however, things change dramatically. Ice and snow create a boundary between you and the ground, allowing you to speed down the hill because the forces of friction are greatly reduced.

Have you ever wondered why people sled downhill? If you combine the force of gravity with the reduced force of friction, a sled will travel downhill easily with just the weight of the sled and its rider.

On flat ground, however, you don't have the added boost of momentum from the slope of the hill. If you want to go somewhere, you'll need a source of power, such as a push from a friend or a pull from an animal.

And that brings us back to the difference between sleds and sleighs. Sleds are smaller vehicles used mainly for recreational activities, like sledding.

Sleighs, on the other hand, are much larger vehicles. They usually have open tops, seats for multiple passengers and must be pulled by animals, such as horses… or reindeer!

In many cold-weather countries, sleighs are used as alternatives to traditional carriages or wagons. They were often the primary means of transportation until the 20th century.

Today, sleighs are still used in many countries as a means of transportation when roads get bad. But the confusion doesn't end with sleds and sleighs!

There are also toboggans (long sleds without runners with a curled front), saucers (round, curved sleds without runners, often made of plastic or metal) and tubes (inflatable plastic sleds that weigh very little).

There are also special sleds used for specific sports. These, too, have their own special names. If you watch the Winter Olympics, you may have seen bobsleds, luges and skeletons!

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