Now, you see it is very important that we have got a proper axis system drawn. This was my x this is my y and rotation; obviously, would be x to y direction, so this is my positive y force, positive v direction and this is my N and r direction. We do not need n and r right now, so I need not have written N and r forget it, but this what it is? Now, think of Y v, this we are doing going to do slowly.