Motion In A Plane (aka X-Y Vector Kinematics with i, j)

Interpreting Acceleration & Velocity Vectors with i's & j's

Before getting into the rather painful business of doing 2-D kinematics vector problems full of i's and j's, it's kind of important to understand what the heck i and j are. (Something tells me that it wouldn't clear things up to tell you that they're also called the "unit direction vectors".) And how you can use them to get the vector components you'll be plugging into your kinematics equations to solve the questions.

Calculating Angles of i & j Vectors

This video shows you how to take a vector with i's and j's in it and calculate the angle (a.k.a. "direction") of the vector. This is a little bit different than your usual physics vector angles, because in this particular section (kinematics with i and j vectors), you're usually supposed to give the angle "relative to the i unit vector".

Vector Acceleration & Velocity Problems
(i & j)

This video covers the problems where they give you an acceleration or velocity vector (in i & j form, naturally), and maybe an initial position vector (also in i & j form, because that sucks more), and then they ask you to figure out the velocity or position a little while later. Also covered, for those few of you who actually have to use calculus in your physics class, is using derivatives to get velocity from the position vector.

Average Velocity Vector Problems (i & j)

Let's face it, at this point we've all calculated average velocity a time or two or ten, amiright? Well, hold onto your hat, because now we're going to do it with i & j-style vectors. Get ready! Omg, totally sweet. Anyways, it's basically the same as always, where you have to divide displacement by Δt. "What," you may ask, "is displacement, and how is it different from the position vector that has i's and j's in it?" Well, this is the video for that too!