Applied anatomy and physiology 1.3b Linear motion, angular motion, fluid mechanics and projectile motion.

Question 1

Describe Linear motion.

Answer 1

Movement of a body in a straight or curved line where all parts move the same distance in the same direction at the same time. Is resultant from a Direct force. Skeleton bobs are a good example in a sport.

Question 2

Describe a Direct force.

Answer 2

A force applied through the centre of mass resulting in linear motion.

Question 3

Define distance, how its calculated and it’s unit of measurement.

Answer 3

Total length of the path covered by a body.
is calculated by measuring the distance.
Measured in Metres M.

Question 4

Define Displacement, how its calculated and it’s unit of measurement.

Answer 4

The shortest straight line route from start to finish.
Calculated by measuring point to point.
Measured in Metres M.

Question 5

Define a Distance time graph.

Answer 5

A visual representation of the distance travelled plotted against the time taken.
Distance is on Y.
Time is on X.
Gradient of the curve indicates the speed.

Question 6

Define a Gradient.

Answer 6

The slope of a graph at a particular moment in time.
Gradient= Change in Y/ Change in X

Question 7

Define a Speed time graph.

Answer 7

A visual representation of the speed of motion plotted against the time taken.
Gradient of the curve indicates acceleration/ deceleration.

Question 8

Define a Velocity time graph.

Answer 8

A visual representation of the velocity of motion plotted against time.
Gradient of the curve indicates acceleration/ deceleration.
A negative curve below the X axis represents a change in the body’s direction.

Question 9

Describe the difference between speed and velocity

Answer 9

Speed is a measurement of distance whereas velocity is a measurement of displacement.

Question 10

Define Angular motion.

Answer 10

Movement of a body or part of a body in a circular path about an axis of rotation.
Resultant of an Eccentric force.

Question 11

Define an Eccentric force.

Answer 11

A force applied outside the centre of mass resulting in angular motion.

Question 12

Define Torque.

Answer 12

A measurement of the turning (Rotational or Eccentric) Force applied to a body.

Question 13

Name the three Axis of rotaton.

Answer 13

Longitudinal.
Transverse.
Frontal.

Question 14

Describe the Longitudinal axis.

Answer 14

Runs from top to bottom of the body.
e.g. Ballerina performing pirouette.

Question 15

Describe the Transverse axis.

Answer 15

Runs from side to side of the body.
e.g. a front somersault.

Question 16

Describe the Frontal axis.

Answer 16

Runs from the front to the back of the body.
e.g. A gymnast performing a cartwheel.

Question 17

Describe the Moment of Inertia (MI)

Answer 17

The resistance of a body to a change in it’s state of angular motion or rotation.

Question 18

Define Angular velocity.

Answer 18

The rate of change in angular displacement or rate of rotation.

Question 19

Define Angular momentum.

Answer 19

The quantity of angular motion possessed by a body.

Question 20

State the calculation for Motion of Inertia.

Answer 20

Moment of Inertia= Sum ( Mass * Distribution of mass from the axis of rotation^2.

MI= Σ M*r^2

Question 21

State the calculation for Angular velocity.

Answer 21

Angular velocity= Angular displacement/ seconds.

x radians/ seconds.

1 radian= 57.3° 2π*radian= 360°.

Question 22

State the calculation for Angular momentum.

Answer 22

Angular momentum= Moment of Inertia * Radians per second.

AM= MI*RPS.

Question 23

Name the two factors that effect Moment of Inertia.

Answer 23

Mass:
The greater the mass the greater the MI. So sports with a high degree of rotation are performed by athletes with low mass.

Distribution of mass from the axis:
When mass is tucked in around the axis the lower the MI.
Body will face less resistant if tucked compared to straight out.

Question 24

Describe Moment of Inertias effect on Angular velocity.

Answer 24

If MI is high, resistant to rotation is high, so Angular velocity is low so the rate of spin is low.
By lowering MI by tucking in mass Angular velocity will speed up causing a greater rate of spin.

Question 25

Describe conservation of Angular momentum.

Answer 25

Angular momentum is a conserved quantity which remains constant unless an external force or torque is applied. Once generated on take off remains constant.

Question 26

Describe Angular analogue of Newtons First law of motion.

Answer 26

The angular equivalent of motion which states: A rotating body will continue to turn about an axis of rotation with constant angular momentum unless acted upon by an eccentric force or torque force.

Question 27

Describe a Projectile.

Answer 27

A body that is launched into the air losing contact with the ground surface, such as a discus or long-jumper.

Question 28

Name the 4 Factors affecting Horizontal distance travelled by a Projectile.

Answer 28

Speed of release. Angle of release. Height of release. Aerodynamic factors.

Question 29

Describe Speed of releases effect on Horizontal distance travelled by a projectile.

Answer 29

Due to Newtons second law, the greater the outgoing speed of the projectile the further it will go.

Question 30

Describe Angle of releases effect on Horizontal distance travelled by a projectile.

Answer 30

Optimal Angle of release is dependant on the Height of release.

Question 31

Describe Height of releases effect on Horizontal distance travelled by a projectile.

Answer 31

If Release height and Landing height are equal then Angle of release should be 45 degrees optimally. If Release height is higher than Landing height Angle of release is less than 45 degrees optimally. If Release height is lower than Landing height Angle of release is more that 45 degrees optimally.

Question 32

Describe Aerodynamic factors effect on Horizontal distance travelled by a projectile.

Answer 32

How the projectile is effected by air resistance will effect it's distance. If the projectile is capable of producing a magnus force will also effect its distance.

Question 33

Describe a Parabolic flight path.

Answer 33

A flight path symmetrical about it's highest point caused by the dominant force on a projectile being Weight.

Question 34

Describe a Non-parabolic flight path.

Answer 34

A flight path Asymmetrical about its highest point caused by a dominant force on the projectile being Air resistance.

Question 35

Describe a Parallelogram of forces.

Answer 35

A parallelogram illustrating the theory that a diagonal drawn from the point where forces are represented in size and direction shows the resultant force acting.

Question 36

Describe the Resultant force.

Answer 36

The sum of all forces acting on a body or the net force acting on a Projectile. This force determines flight path.

Question 37

Describe an Aerofoil.

Answer 37

A streamlined shape with a curved upper surface (Air moves faster here) and flat lower surface (Moves slower here) designed to give a body additional lift force.

Question 38

Describe a Lift force.

Answer 38

An additional force created by a pressure gradient forming on opposing surfaces of an aerofoil moving through a fluid. Can increase the time a projectile hangs in the air.

Question 39

Describe Angle of attack.

Answer 39

The most favourable angle of release for a projectile to optimise lift force due to Bernoulli's principle.

Question 40

Describe Angle of attack.

Answer 40

The most favourable angle of release for a projectile to optimise lift force due to Bernoulli's principle.

Question 41

Describe a Downward lift force

Answer 41

If the aerofoil is inverted the pressure gradient will be flipped so force will be applied downwards, F1 cars use this to increase friction around corners.

Question 42

Name 4 types of Spin

Answer 42

Topspin. Backspin. Sidespin Hook. Sidespin Slice.

Question 43

Describe Topspin.

Answer 43

Eccentric force applied above the centre of mass causing it to spin downwards around the transverse axis and creating a downwards Magnus force.

Question 44

Describe Backspin.

Answer 44

Eccentric force applied below the centre of mass causing it to spin upwards around the transverse axis and create a upwards Magnus force.

Question 45

Describe Hook spin.

Answer 45

Eccentric force applied to the right of centre of mass causing it to spin left around the Longitudinal axis creating a magnus force going left.

Question 46

Describe Slice spin.

Answer 46

Eccentric force applied to the left of the centre of mass causing it to spin right around the longitudinal axis causing magnus force going right.

Question 47

Describe a Magnus force.

Answer 47

A force created from a pressure gradient on opposing sides of a spinning object moving through the air.