3.2.2.5 Projectile motion (incl. 3.2.2.6 Fluid mechanics) GapFill

Bernoulli's principle can be applied to the mechanics of different sports movements and can be exploited to optimise performance. The principle is based on the effect that the surrounding airflow, and the pressure of that air, has on the body or object in motion.

Bernoulli's principle for upward lift force

When applied to projectiles, Bernoulli's principle is applied to achieve upward lift force. A prime example is the  shot-putlong jumpdiscushigh jump in field athletics, where the aim of the event is to launch the projectile to achieve the greatest  vertical accelerationhorizontal forcevertical distancehorizontal distance possible. Upward lift force can be achieved by adopting an angle of  attackdefencelandingapproach – that is the optimal release angle to achieve the greatest distance. The optimal angle when a projectile is launched at a slight elevation above ground level, as is the case with the discus, is said to be  90403050º. Bernoulli's principle explains why this is the optimal angle:

As an object or a body is in motion, a pressure  voidconcentrationvacuumgradient is created between the upper and lower surfaces of that object or body. In the case of the discus travelling at an optimal release angle, the flow of air across the upper surface of the projectile is  fasterslowermore disruptivethe same than the flow of air across the lower surface. As the speed of air increases, the pressure of that air on the object decreases. Therefore, the air pressure on the upper surface of the discus is  less disruptivethe samehigherlower than that on the lower surface. An object is forced towards the region of higher air pressure, thus producing an upward lift force on the discus which extends its duration in flight and ability to accumulate horizontal distance.

Bernoulli's principle for downward lift force

The opposite effect is desired in sports where downward lift force is beneficial, such as motor racing, cycling, and  javelinfootballthe 100 mskiing. Therefore, the aim with the design of equipment in these sports is achieving a fast flow of air below and slowing or disrupting the flow of air above. Applying Bernoulli's principle to this would mean that the air pressure is  lowerslowergreaterfaster beneath each object than it is above, providing a downward lift force which improves traction against the road, track or slope.