Hopper car

Okay, imagine you're playing with your toy trains on a track. You have a little car that you can fill up with candy or other toys. Now imagine a big train that's many times bigger than your toy trains. Instead of a little car, they have a hopper car that's just as big as a room!

Hopper cars are train cars that are used to transport things like coal, grain, and other materials. They're called "hopper" cars because they have a big open top that looks like a funnel, so you can easily pour things into them.

If you had a hopper car, you could pour in all sorts of things: maybe you want to fill it with candy, or with dirt, or with your favorite toys. Then you could close up the top, attach it to your train, and travel across the country!

And the cool thing about hopper cars is that they can also unload their contents without needing to be lifted up or turned over. They have a little door at the bottom that can open up, and then the things inside can just fall out.

So a hopper car is basically a giant train car that you can fill up with things and easily empty out again.