## Overview This topic covers the idea that centripetal force is the resultant force that acts on a body moving at constant speed in a circle, and that it acts towards the centre of the circle. Defining terms for circular motion are introduced and the equations relating to circular motion are derived. ## Working Scientifically This unit contains opportunities for learners to apply scientific knowledge to practical contexts. ## Mathematical Skills There are a number of opportunities for the development of mathematical skills in this unit. These include using calculators to find and use power expressions; making order of magnitude calculations; understanding and using the symbols: =, <, <<, >>, >, ∝, ≈, ∆; changing the subject of an equation, including non-linear equations; using angles in regular 2D and 3D structures. ### Learners should be able to demonstrate and apply their knowledge and understanding of: (a) the terms period of rotation, frequency (b) the definition of the unit radian as a measure of angle (c) the use of the radian as a measure of angle (d) the definition of angular velocity, ω, for an object performing circular motion and performing simple harmonic motion (e) the idea that the centripetal force is the resultant force acting on a body moving at constant speed in a circle (f) the centripetal force and acceleration are directed towards the centre of the circular motion (g) the use of the following equations relating to circular motion v r = , 2 a r =  , 2 , v a r = 2 , mv F r = 2 F m #Component1