Biomechanics 3.3 Fluid mechanics Flashcards
What is air resistance
the force that opposes the direction of motion of a body through the air
What is drag
the force that opposes the direction of motion of a body through the water
What does air resistance and drag acting against the motion of a body cause fatigue
places an increased physiological demand- can lead to early fatigue and poor performance
What can minimise air resistance and drag
body position, equipment design and clothing
4 main factors that affect the magnitude of air resistance and drag on body
Velocity
frontal cross sectional area
streamlining and shape
surface characteristics
How does velocity affect the magnitude of air resistance and drag of a body
the greater the velocity, the greater the air resistance of drag
eg track cycling, speed skating, downhill skiing are all greatly affected due to high velocities
How does Frontal cross sectional area affect the magnitude of air resistance and drag of a body
larger FCSA, the larger the air resistance or drag
eg track cycling or downhill skiing greatly affected due to large FCSA of the body facing oncoming air
How does Streamlining and shape affect the magnitude of air resistance and drag of a body
the more streamlined or aerodynamic the shape of the body in motion, the lower the air resistance or drag
more aerodynamic the shape- lower air resistance or drag will be
most sports use a tear-drop or aerofoil shape, such as track cyclist, downhill skier or speed skaters helmet
What is streamlining
the creation of smooth airflow around an aerodynamic shape
What is an Aerofoil
a streamlined shape with a curved upper surface and flat lower surface designed to give an additional lift force to a body
How do surface characteristics affect the magnitude of air resistance and drag of a body
the smoother the surface, the lower the air resistance or drag
participants in sports such as cycling, swimming, sprinting etc wear engineered clothing to create the smoothest surface possible to reduce the friction between the fluid and the body surface
For downhill skiing- what do they do to maximise performance and battle against air resistance
- minimise frontal cross sectional area by adopting a low crouched position in the straights and jump sections
-wear aerofoil helmets to create a streamlined shape
-wear super silky lycra suits to create a smooth surface
What are tactics used by team GB to optimise bike, equipment, body position and team tactics to minimise air resistance
lightweight carbon fibre bicycle design- minimise air resistance
aerodynamic riding position
aerodynamic helmets
tight-fitting lycra
What is projectile motion
the movement of a body through the air following a curved flight path under the force of gravity
The horizontal distance travelled by a projectile affected by four factors- what are the 4 factors that affect horizontal distance travelled by projectile
speed of release
angle of release
height of release
aerodynamic factors
What is projectile
a body that is launched into the air losing contact with the ground surface, such as discus or a long jumper
How does the speed of release affect horizontal distance
due to newtons second law of acceleration,
the greater the force applied to the projectile , the greater the change in momentum
and therefore acceleration of projectile in air
How does the angle of release affect horizontal distance
based on projectile being released at the same speed from the ground, at a release angle of…
90 the projectile will accelerate vertically upwards and come straight back down, traveling 0m
45-optimal angle to maximise horizontal distance
anything higher than 45 will reach peak height too quickly
What is the optimal angle of release
45 if the release height and landing height are equal
What is a parabolic flight
if weight is the dominant force and air resistance is very small
What is a non paraboloic flight path
if air resistance is the dominant force and weight is very small
