1. Quick Questions What is moment of inertia?
What affects moment of inertia?
What is Angular motion measured in?
What is angular momentum affected by?

2. Biomechanical Principles - Projectile Motion
Biomechanics
Biomechanical Principles - Projectile Motion

3. Learning Objectives Learning Objective:
Understand the what affects the flight of a projectile in motion
- free body diagrams, resolution of forces, flight paths, Bernoulli’s principle, Magnus force
All – describe how factors affect distance travelled of a projectile
- Draw free body diagrams on a projectile in flight (W & AR)
Most – describe the effects of the parallelogram of forces acting on a projectile in flight
- Some – apply bernoulli’s principle to a discus, javelin, ski jumper, f1 car and track cyclist.
- apply the theory of magnus force to deviations in flight patterns
Few – use their knowledge to explain the flight patterns of projectiles and how athletes can use their knowledge to maximise their performance

4. Free body diagrams (W & AR)
Shuttlecock
Javelin
Shot put
See book 2 pages

5. FBD of a shuttle cock
Size of AR decreases as velocity is reduced, which has been caused by the AR. AR W
AR force is small as shuttle has slowed.
Weight force remains the same throughout and is now larger than AR, resulting in the shuttle dropping. AR W
AR is much larger than W as the velocity of shuttle is high as it leaves the racket head. W AR

6. Factors affecting horizontal distance travelled by a projectile
Height
Speed
Angle of release
? How do you think each of these affect the distance travelled ?

7. Resolution of forces acting on a projectile in flight using the parallelogram of forces
See book 2 pages 98 – 103
To consider the result of all forces acting on a projectile in flight a parallelogram of forces can be drawn
This shows the resultant force acting on a projectile (sum of all forces / net force) AR W
Resultant Force

8. Patterns of flight paths
parabolic non-parabolic
- parabolic flight pattern – affected by angle (cannonball)
- graphs showing flight paths of a javelin thrown at different release angles and speeds

11. Spin
Magnus Effect
– Roberto Carlos Free Kick
– Football physics – the ‘impossible’ free kick
– Killerspin Table Tennis Technique: ball and spin
– side/back spin Table Tennis Serve Tutorial
Athletics Engineered: How a Curveball Curves
What is magnus force -
The magnus effect explained -

12. Take notes and Draw diagrams showing the effects of spin (from books)
Top spin
Back spin
Side spin
You must show
- Direction of motion
Direction of spin
Direction of airflow
Where the air is at higher and lower pressure

20. Side Spin

21. Exam Questions
June b) Explain how a performer generates spin on a ball and describe the effects of spin on the bounce of a ball. (5)
Jan c) Explain how a lift force is imparted to a discus during flight and describe its effects on the flight path of the discus. (6)
June c) Describe the effect of topspin on the flight path of a ball. Explain the effect that topspin has on the bounce of a ball. (5)

22. Exam Questions
Jan c) Use a diagram to work out the resultant force acting on a hard hit badminton shuttle during the early stages of the flight path of a long serve. Explain the effect of the resultant force acting on the flight path of the shuttle. (5)
June c) Compare the shape of the flight path of a shot putt with that of a fast moving badminton shuttle. Explain the reasons for the differences in their respective flight paths. (4)
Jan d) Sketch a free body diagram to show the forces acting on a ball with topspin during flight. Examine the effects of different types of spin on a ball during flight and when bouncing. Evaluate the advantages and disadvantages of each type of spin in sport. (20)