2 Dimensional Motion

Fall 2008 Rick Mills Art 130 Introduction to Glass at UH Manoa
These are the projects that I did.

Preface: This tutorial explains motion in 2 dimensions. I assume you know that "Vi" is initial velocity, "Vf" is final velocity, "-delta-X" is change in X, a is acceleration, and "t" is time... I also assume prior knowledge of algebra. This may be comprehensive but I'm not gonna teach you algebra, or how to ride elephants... just 2 dimensional motion.

Ok lets assume that we put your sister in a wagon. (if you dont have a sister you cant do physics)

Your sister in a wagon

If we just roll her around that is only in one dimension. so...

Lets put the wagon on a catapult

Your sister in a wagon... on a catapult

Now we are going to launch her at 92 meters / second at 30 degrees above the horizontal. (yes that is about a foot ball field a second)

92 meters per second at 30 degrees...

Now what we want to know is where to put the comicly small pool of water for her to land in.(-deltaX- (not a spy))

I suggest you first write down the "Big 3" equations.

Big 3 equations

I also write out a table I will fill in for all my motion problems (not gyrating or kicking people, just for physics)

a very helpful table

Now we know that we are looking for how far your sister will fly (thats right your sister IS fly ;) ). To do this we are going to need to use the big 3 equations. We can not just find how far she flys because to find how far she goes we need to know how fast she is going in a horizontal direction, and for how long.


The sin of the angle times the speed of the hypotonuse (the angled direction) will tell us how fast she is flying up, cos of the angle multiplied by the hypotonuse will give us her horizontal speed. Now we can fill in our table with what we know.

a very helpful table full of useful information we know about your sister.

Because we do not know the amount of time your sister will be flying along the horizontal we need to find the time. Because of magic the amount of time she will be flying horizontally is the same as the amount of time she is flying both up and down. And since we have enough information to find how long she is flying up and down ... we do so (because we CAN!)

more math! with numbers in it

This shows how long it takes her to reach the apex of he flight up. Again because of magic we know that it will take the same amount of time for her to come down (yes magic). So now we can fill in the rest of our table for the motion in the X ;)

a very helpful table full of useful information we have learned about your sister.

Now we can calculate how far she will fly using a "Big 3" equation.

where your sister will land... theoretically.

And thus your sister will fly 747.30 meters.

Special thanks to: Your sister ;)

Don't launch children out of catapults unless supervised by trained professionals