The powerpoint shows an object moving in a circle. Its aim is to explain the difficult concept of how an object moving in a circle at constant speed is accelerating. It explains this in terms of changing velocity and in terms of their being a resultant force. It emphasizes that the object is not in equilibrium and there is no outwards force. It shows how an object flies off along the tangent when the centripetal force ceases. The first file has student notes which explain why an object moving in a circle at constant speed is accelerating towards the centre of the circle. It goes step by step through this difficult concept. It refers to Newton’s First Law, centripetal force, centripetal acceleration, the definition of velocity and the definition of acceleration. It explains why the velocity changes yet the speed does not change. It gives examples of circular motion and explains the relationship between centripetal force and the mass, speed and radius of orbit of the object. It also relates the speed to the radius of orbit and the time period. There are words to be completed by the student as the teacher explains each step. The third, and last, page has questions designed to check on the understanding of the previous two pages. There is NO reference to the equation F = mv2/r. The second file has the missing words and answers to the questions.