fluid mechanics and projectile motion Flashcards
what is fluid mechanics
the study of the forces acting on an object through air or water
what two factors are important to consider when playing sport
air resistance
drag
what is air resistance
is a force that opposes the motion of the boy traveling through air
what is drag
resistance in the water i referred to as drag, it will depend on the environment
what does air resistance and drag depend on
-the velocity of the moving body- increase in velocity results in greater resistance
-the front cross-sectional area of the moving body- the larger the cross-sectional area, the greater the air resistance
-shape and surface characteristics on the moving body- a streamline shape results in less resistance
-mass of an object- heavier objects will have less than an effect on air resistance, lighter objects will be affected more by air resistance
what is projectile motion
refers to the motion of either an object or the human body being ‘projected’ into the air at an angle by an external force
what are the three factors that will determine the horizontal distance that a projectile can travel
angle of release
speed of release
height of release
what is angle of release
the optimal angle of release is 45 degrees
it is dependant upon the release height and landing height
waht happens to the landing height and release height if optimal release angle is lower
is higher
what happens when speed of release is increased
greater the horizontal distance travelled
what happens if release height is greater than landing height
release is less than 45 degrees
what happens is release height is lower than the landing height
optimum angle of release is lower than 45 degrees
what happens to projectile in flight
describes as parabolic shape.
if weight is the dominant force the air resistance is less effective and a parabolic flight occurs
if air resistance is dominant over weight a non-parabolic light path will occur.
what is a parabolic flight path
a symmetrical flight path.
what sporting example is parabolic flight path
shot put
weight provides more of a resistance than air resistance, meaning air resistance doesn’t have an affect causing a parabolic flight path
what is a non-parabolic flight path
a non symmetrical path
what is a sporting example of a non parabolic flight path
badminton shuttle, when a shuttle has been hit into the air, air resistance is the major form of resistance , due to the light mass of the shuttle and the high velocity of release
how can projectile flight be illustrated
free body diagrams, this is a snapshot of the forces acting on the object at 3 phases of motion (start,middle and end)
what is the bernoulli principle
states that the higher velocity of air flow and the lower the surrounding pressure this principle is the reason additional lift force can be applied to a projectile when thrown.
what is upward lift force in bernoulli principle
an aerofoil shape has a curved upper and a flat underneath surface, the resultant effect is a law pressure above the object and a higher pressure below it, all fluids move from high to low pressure and therefore created lift
what is the downward lift force in bernoulli principle
if the aerofoil is inverted, it will create a downwards force
what is the magnus effect and spin
applying an external force outside the centre of mass results in spin
what are the 4 types of spin applied to an object
topsin
backspin
sidespin- left and right
what is topspin
eccentric force applied about the centre of mass
