Biomechanics

Question 1

Newtons three laws of motion

Answer 1

1) Law of inertia
2) Law of Acceleration
3) Law of action/reaction

Question 2

1) law of inertia

Answer 2

Unless acted upon by an external force, an object at rest remains at rest.
In motion it continues to move in a straight line with constant speed.

Question 3

Inertia

Answer 3

The force required to change the state of motion.

Question 4

2) Law of acceleration

Answer 4

A force upon an object causes it to accelerate, according to F = M x A.

Question 5

3) Law of action/reaction

Answer 5

For every action (force) there is an equal and opposite reaction.

Question 6

COM (centre of mass)

Answer 6

Where its mass is considered to be centred.
Can be defined as the ‘point of balance’.

Question 7

4 factors COM depends on

Answer 7

Height
Weight
Muscle mass
Body shape
(also changes when we alter position, which happens frequently in sport)

Question 8

4 factors affecting stability

Answer 8

1) Height of the COM
2) Area of base of support
3) Position of the line of gravity.
4) Mass of the performer.

Question 9

Fulcrum

Answer 9

The axis around which the lever rotates.

Question 10

Load

Answer 10

The force of the thing that you want to move.

Question 11

Effort

Answer 11

The force that is applied by the user of the level system.

Question 12

FLE 123

Answer 12

1 = fulcrum in the mid.
2 = load in the mid.
3 = effort in the mid.

Question 13

1st class lever

Answer 13

Fulcrum in the middle.
Nodding head, rowing, tricep dip.

Question 14

2nd class lever

Answer 14

Load in the middle.
Calf raise, take off in long jump.

Question 15

3rd class lever

Answer 15

Effort in the middle
Kicking a ball, bicep curl.

Question 16

Mechanical advantage formula

Answer 16

Mechanical advantage = effort arm / load arm.

Question 17

Mechanical advantage

Answer 17

When a large load can be lifted with relatively little effort.

Question 18

Mechanical disadvantage

Answer 18

When it takes a lot of effort to life a relatively small load.

Question 19

Lever system with mechanical advantage

Answer 19

2nd class, as effort arm (Effort to fulcrum) being longer than load arm (load to fulcrum), as load in the middle

Question 20

Lever system with mechanical disadvantage

Answer 20

3rd class, as load arm (load to fulcrum) being longer than effort arm (effort to fulcrum) as effort in middle.

Question 21

Linear motion

Answer 21

A one-dimensional motion along a straight line.

Question 22

Static Frictional force

Answer 22

The force exerted on one surface by another when there is no motion between the two forces.

Question 23

Sliding frictional force

Answer 23

When dry friction acts between two surfaces moving relative to one another.

Question 24

Internal muscular force

Answer 24

Force generated by the skeletal muscles

Question 25

Weight

Answer 25

Weight = mass x acceleration, measured in newtons

Question 26

Scalar quantity

Answer 26

Magnitude but no direction.

Question 27

Vector quantity

Answer 27

A magnitude as well as direction to describe movement from one point to another.

Question 28

Impulse

Answer 28

Time it takes for a force to be applied to an object or body.

Question 29

Equation for impulse

Answer 29

Impulse (Ns) = Force (N) x Time (s).

Question 30

Acceleration impulse graph

Answer 30

Question 31

Constant Speed impulse graph

Answer 31

Question 32

Deceleration impulse graph

Answer 32

Question 33

Angular motion

Answer 33

Movement that takes place around an axis.

Question 34

Torque

Answer 34

The force created that turns the body around an axis.

Question 35

Newtons 1st angular law

Answer 35

A rotating body will continue with constant torque until a large enough external force is acted upon it.

Question 36

Newtons 2nd angular law

Answer 36

The rate of change of angular motion is proportional to the force changing it.

Question 37

Newtons 3rd angular force

Answer 37

When torque is applied, there will always be an equal and opposite force.

Question 38

Angular displacement

Answer 38

The smallest change in angle between start and finish points of rotation.

Question 39

Angular velocity

Answer 39

The rotational speed of an object.

Question 40

Angular acceleration

Answer 40

The rate of change of angular velocity.

Question 41

Angular momentum equation

Answer 41

Angular motion = moment of inertia x angular velocity.

Question 42

How to increase angular motion

Answer 42

Decreased moment of inertia by tucking in limbs.

Question 43

Horizontal displacement

Answer 43

The shortest distance from the starting point to the finishing point.

Question 44

2 factors affecting horizontal displacement

Answer 44

Gravity and Air resistance.

Question 45

Three factors affecting flight path

Answer 45

Height, Speed, Angle of release.

Question 46

Parabola

Answer 46

Flight path

Question 47

Vector diagram

Answer 47

Question 48

Two main principles of fluid dynamics

Answer 48

Surface drag and form drag

Question 49

Surface drag

Answer 49

Refers to friction. E.g. the friction created when a football rolls across the grass to slow it down.

Question 50

Form drag

Answer 50

Refers to streamlining. E.g. cyclists maximising their speed by getting in a low position.

Question 51

Bernoulli principle

Answer 51

The angle of release of an object affects how air passed over the top and bottom of an object. This is because air molecules exert less pressure when they travel faster. And more pressure when they travel slower.

Question 52

Upward lift

Answer 52

Release at optimum angle (45) Air will travel quickly above the discuss, causing low pressure. Air will travel slowly below discuss, creating high pressure. Pressure moves from high to low causing the discuss to lift higher into the air and travel further.

Question 53

Downward lift.

Answer 53

Cyclist will get into a low, streamlined position. Air will travel slowly above cyclist, causing high pressure. Air travels quickly against the cyclist, causing low pressure. Pressure moves from high to low allowing the cyclist to keep speed whilst cornering.