 This video is going to be an introduction to 2D kinematics. In 1D kinematics, we have shortly talked about position. Usually we use the letter S for position. Probably comes from German standard, which means so much as location. Now in 1D, this was plus or minus position in X or position in Y. It is a vector as we have magnitude and direction indicated with plus or minus. Now in 2D, this is going to simply be having an X component plus or minus a Y component. Next, we had velocity, which is simply the derivation of dS over dt. In 1D, this meant it was plus or minus velocity in X. Now we have plus or minus velocity in X and plus or minus velocity in Y. Now what does this mean in practice? For practice here, we could have had velocity that was going this way, while our plus direction was this way, plus X. And then I would just have written plus, for example, 5 meters per second. Now in 2D, we could have a velocity that has an X component and a Y component. And we're going to be saying that to the right is my vector called I hat. And to the top, it's my vector called J hat. I hat in X, J hat in Y. So I'm going to have, for example, 1, 2, let's say plus 3I hat. This is the X component plus let's say 2J hat. So this one here is my velocity in X, I'm velocity in Y. So the big difference is that instead of having only one direction, now we have two directions. And you could probably guess in 3D we just add a component in set direction.