Apply Newton’s second law of motion to the distance travelled by a golf ball after being struck.

Outline how the Bernoulli principle affects a golf ball in flight.

Outline different types of drag and ways they can be reduced in swimming.

Discuss reasons for recovery following a soccer game.

the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, and inversely proportional to the mass of the object
OR
F = ma ✔

the ball will travel in the same direction as the direction of the net force applied to the ball ✔

when the club contacts the ball, the change in momentum of the club is transferred to the ball/conservation of momentum ✔

the greater the change in momentum of the ball, the longer distance the ball will travel
OR
the greater the impulse applied to the ball, the longer distance the ball will travel ✔

larger clubs /club with greater mass will generate a greater force and therefore propel the ball further
OR
a lighter golf ball will accelerate faster when struck by the golf club ✔

Accept annotated diagrams for suitable mark points.

[4 max]

the Bernoulli principle explains how relative air pressure «from backspin» around a golf ball means that it experiences a lift force and travels further through the air ✔

as a golf ball travels with backspin, it experiences higher air pressure on the bottom of the ball and lower air pressure on the top of the ball ✔

the ball/object is attracted to the area of lower air pressure, which is above the ball and therefore experiences lift ✔

the lift force is perpendicular to the direction of the airflow ✔

the faster the ball travels / spins, the greater the differences in relative air pressure and therefore the greater the lift force ✔

the dimples on the golf ball encourage small turbulent air, which protects the ball against drag force ✔

a ball struck off «laterally» centre will spin in the air, therefore creating lower relative air pressure on one side and generating curve ✔

Accept annotated diagram to outline the principles.

[5 max]

Surface drag:

outer surface of body catches a layer of neighbouring fluid as it moves ✔

reduced by creating smooth surface / shaving / shark suit ✔

Form drag:

reaction of fluid when a body pushes against it ✔

proficient / streamlined swimming technique reducing turbulence ✔

Wave drag:

caused by the displacement of fluid (usually water), as the body moves along the surface ✔

swimming underwater for as long as possible ✔

wave-less pools designed to reduce wave drag ✔

Award [1 max] for list of types of drag, still awarding more marks for methods.

Award [2 max] per type of drag.

[6 max]

recovery is vital to achieve physiological adaptations ✔

purpose is to return the body to pre-game state as quickly as possible
OR
purpose is to refuel / rehydrate / lower body temperature / lower heart rater to resting heart rate ✔

recovery rate depends on activity type (intensity and duration – dependent on position) ✔

recovery rate affected by athlete condition ✔

Excess post-exercise oxygen consumption (EPOC) for:

restoration of muscle creatine phosphate stores ✔

removal of lactic acid ✔

replenishing myoglobin stores with oxygen ✔

replacement of muscle / liver glycogen stores ✔

[5 max]

Generally students were able to access 1 mark for the definition and 1 mark for a simple application. Very few candidates were able to access 3 or 4 marks.

Many candidates understood the Bernoulli principle and could identify the pressure differences correctly; however, many candidates also discussed top spin.

Many candidates were able to identify methods that reduce drag in swimming. Few candidates were able to truly describe the three types of drag, often mixing their methods to reduce drag with the wrong type.

Many candidates struggled to refer to the stages of EPOC and consider the return to resting levels. Many focused on DOMS and how to reduce stiffness and injury.