Projectile Motion ?v=-uUsUaPJUc0

2 Projectile motion Vertical motion is affected by gravity – Horizontal motion is affected by friction – Vertical component Horizontal component it is continually decreasing which can be negligible

3 Variations in vertical and horizontal components This causes the observed parabolic flight and affects the motion components as follows:

4 Projectile motion Factors affecting distance travelled: Speed of release Height of release Angle of release

 The optimum angle of release a a projectile depends upon the relative heights of release and landing  RH = LH optimum angle is 45 deg  RH > LH optimum angle is less than 45 deg  RH < LH optimum angle is greater then 45 degrees  Examples of these?

Flight Paths  Parabolic Air resistance negligible follows parabolic or symmetrical flight path  Distorted Air resistance is great, projectile veers away from normal flight path to asymmetrical or distorted flight path Sporting examples?

7 Impulse   Measured during – force platforms on track  Displayed as Force x time sprinting Force x time graph

8 time force negative positive Impulse = force x time shown as area under graph

9  Impulse is mainly concerned with  Involves  Two parts single events – a footfall horizontal forces only to a footfall landing – negative horizontal forces Push-off – positive horizontal forces

10 Typically time force neg pos Landing - negative impulse Push-off - positive impulse Net impulse is difference between positive and negative impulses

11 Typically time force neg pos Small negative impulse Large positive impulse Net impulse is positive – performer is accelerating

12 Typically time force neg pos Large negative impulse Small positive impulse Net impulse is negative – performer is decelerating