Inertia is an object's resistance to changes in motion. The heavier an object, the greater its inertia and the more force needed to move or stop it. Momentum is an object's mass multiplied by its velocity. Impulse is the force applied to an object over time. The greater the force or longer it is applied, the greater the impulse. Sports involve all three basic types of motion: linear, where all parts move the same distance in the same direction at the same time; angular, where the body rotates around an axis; and general, which is a combination.

1. More Biomechanical Terms

2. Inertia Inertia is the term used to describe a body's resistance to a change in its state of motion Think of it as an objects resistance to beginning movement The heavier the object, the greater its inertia and therefore the greater the force required to move it or change its state of motion

3. Activity 1 In pairs, chest-pass the basketball and medicine ball over three distances (1m. 3m, 5m) Which ball has the greater inertia? Which ball is easier to throw over longer distances? Why? Note which ball is more difficult to catch or stop (this will be referred to again when discussing momentum)

4. Activity 2 Write down 5 sporting examples of Inertia A stationary soccer ball resting on the pitch

5. Momentum The momentum of an object is equal to its mass or weight X by its velocity Momentum – Mass X Velocity Therefore, an object can only have momentum if it is moving. The greater its momentum, the further it may travel and the harder it is to stop or slow the object

6. Activity 3 In the above picture, let's say that the mass is 2.0 kg and that the velocity is 4.0 m/s. That is: m = 2.0 kg v = 4.0 m/s Using the formula work out the objects momentum and express it in kg-m/s

7. Some More m = 4.36kg V = 15 m/s = M= 15.47kg V = 35m/s =

8. Activity 4 Explain why the principal of momentum is important in sports and sports competition

9. Impulse The concept of impulse is best described by the following formula Impulse= Force X Time In this equation force equals the objects mass X by its acceleration and time equals the length of time for which the force is applied to the object The longer a force can be applied and the greater the force applied, the greater the objects impulse

10. Types of Motion

11. 3 basic forms of Motion Linear Angular General

12. Linear Motion Linear : ALL parts of the body move through the same distance, in the same direction, in the same time List 3 other examples of Linear Motion

13. Angular Motion Angular (rotation): The body moves in a circular path around an axis of rotation so ALL parts of the body move through the same angle , in the same direction , in the same time List 3 Examples of Angular Motion

14. General Motion General : Combination of linear and angular, and is the most common in human movement

15. Sport/Activity Linear Angular General 100m sprint Tobogganing down a hill Teeing off at golf The shoulder in a cricket bowling action Cycling Going down a slide An ice skater spinning