 Now we can look at non-uniform circular motion. Remember in uniform circular motion, we had that the object moves in a circular path. And that means that my radius is constant all the way around the circle. But we also have that the object moves at constant speed. So my V is constant everywhere around the circle. For non-uniform circular motion, I still have the object moves in a circular path with a constant radius. But now the object moves at a variable speed. So my V is changing at different points around the circle. Now there's a lot of different ways that the speed could change. It could be speeding up like the example I just showed where at every point around the circle it's going a little bit faster than it was before. You could also have slowing down. That might happen if you got friction somehow involved in the system. Another common one is to have it slower at the top and faster at the bottom. So this will happen when you've got gravity involved in some sort of vertical circular motion. Now we've got accelerations involved here. Because I've got a changing speed, that means I've got a tangential acceleration. Because it's circular motion I've got a changing direction, so that means I've got a radial acceleration. And for circular motion we can refer to our centripetal acceleration in terms of a specific equation for that radial acceleration. So that leads us to our force equations. We want to use two components. But instead of using x and y, I'm using my tangential component and my radial component. In this case I've left my tangential acceleration as just At. But for my radial acceleration I went in and had put the negative for inward and my centripetal acceleration. And as always with your force equations you're going to have to figure out which physical forces are in the tangential and the radial directions. And a physical force might have components in each of those. But more than that we also have to recognize that it's going to be different at each point around the circle. If nothing else your velocity is changing as you're going around. And so that's going to cause you to have different amounts of radial forces at each point around the circle. Also you could have a difference in exactly which physical forces are in which direction at any particular point around the circle. So you can find the specifics for a specific moment that's going around the circle. But you still have to take into account all the other factors and all the other places around the circle. So that's our non-uniform circular motion.