 Now, let's move on to the second ingredient on our acceleration, which is the change in time. Since we know that the speed of our uniform circular motion is V, we can work out the change in time with delta t from the distance it travels. So we'll redraw a diagram with the object at two points along the circle. Now, as we know from circle geometry, the length that the object travels is equal to the radius of the circle times theta, the angle in radians over which the object is travelled. Therefore, we can find that the distance the object has travelled is r times theta. We also know that the speed the object is travelling at is equal to V, the speed. We can now plug this back into our change in time to give us the change in time is equal to r theta on V. We now have expressions for both delta V and delta t, so we're almost there. So the acceleration is equal to the change in velocity over the change in time, and we're looking at an instantaneous moment in time. If we plug in our values, we find that our acceleration is equal to V theta divided by r theta divided by V.