How would you like to see into the future? Would you like to know what's going to happen before it happens? Most people would. But that's impossible, isn't it? No one can see into the future, right? Hold on there. While we may never be one hundred percent sure about what will happen, we can still come pretty close. You just need a few words about how things move and then you can see a couple of steps forward in time. Or at least make a very good guess.
The first step is very easy. In order to see the future, we must first know that things move. The Earth spins. Your hand waves hello. Your eyes move across these words. Motion
is when something moves. When you see something moving, you can guess where it will end up. Knock a glass off of a table, and you can probably figure out what will happen next. You will need more than this to really see into the future, though. Now, if you would just use motion to move your eyes to the next paragraph, that would be helpful.
Great. Hey, you're a pretty good reader. Your eyes might fly along these words or they may go along slowly. Speed
is how fast something moves. A car zooming down the freeway moves at a speed. A snail inching along the sidewalk moves at a speed. They just have very different speeds. When you can see the speed of something you can tell how long it will be before it gets where it's going. If you see a snail inching toward your sandwich on the grass, you can relax. If you see a squirrel bounding toward your picnic, you might want to grab your sandwich before it gets eaten.
How do you expect me to move fast, I don't have any feet!
Just because you know the speed of something does not mean you know much else about it. There are a couple more things you need to think about. Distance
is how much space there is between things or people. If you want to figure out the future, it's good to know how far away something is. If the snail is one inch away from your sandwich, you might want to grab it. If the squirrel is bounding a thousand miles away from your sandwich, your sandwich is safe . . . for a while, at least.
I may be cute but I'll still eat your sandwich.
Even knowing how fast something is moving or how far it has to go is not enough to see what's going to happen. There's one more piece of the puzzle. Can you guess what it is? What if that snail that's only an inch away was crawling away from your sandwich? Velocity
is the speed and direction that something is moving. We might say the speed of something is 35 miles per hour. The velocity of something will read 35 miles per hour north. Don't worry, I think that snail would rather eat the grass than your sandwich.
Knowing how something is moving could help you see into the future. If you know its motion, you can know that it is moving. If you know its speed, you can tell how fast it is moving. If you know the distance it has to go, you can guess how long it will take to get there. And if you know its velocity, well, you just might be able to figure out where it's going to end up. By keeping these things in mind, you could guess what is going to happen and maybe even stop bad things from happening. Or just don't leave your sandwich where a snail or squirrel could get at it.
Physics 4 Kids. "Velocity, Speed, and Motion"¦ Oh My!" Physics 4 Kids, 2009. <http://www.physics4kids.com/files/motion_velocity.html>