Biomechanics

Question 0

Definition of force

Answer 0

The action causing the load to move

Question 1

Definition of a fulcrum.

Answer 1

An axis or pivot point

Eg elbow

Question 2

Definition of a lever

Answer 2

A rigid bar resting on a pivot, used to move fixed load when force is applied to the other side

Question 3

In relation to lever length. Explain what happens when force increases

Answer 3

Force arm length increases

Resistance arm length decrease

Question 4

In relation to Lever length. Explain what happens when there is an increase In speed

Answer 4

Force arm length decreases

Resistance arm length increase

Question 5

Explain Class 1 lever with example

Answer 5

Axis is between resistance point & force application magnifies force applied.
Eg Head & Neck

Question 6

Explain a 2nd class lever with example

Answer 6

Axis is at the end of the lever and the resistance is between the axis and force.
Eg wheelbarrow

Question 7

Explain a class three lever include an example

Answer 7

Axis is at the end of the lever and the force is applied between the axis and resistance.
Eg most muscles

Question 8

Explain a Concentric contraction

Answer 8

Muscle gets shorter

Forces decreases as the velocity of shortening increase

Question 9

Explain an eccentric contraction

Answer 9

Muscle gets longer

The force resistance increases as the velocity of lengthening increases

Question 10

Newtons 1st law

Answer 10

Inertia- an object at rest tends to stay at rest, until acted upon by another force.
Eg train moving and coming to a stop

Question 11

Newtons 2nd law

Answer 11

Force & Acceleration, when a body is acted upon by a force it’s resulting change in momentum is proportional to the force changing it.

Question 12

Newtons 3rd law

Answer 12

Action reaction, for every action there is an equal and opposite reaction whenever one object exerts a force on the 2nd object.

Question 13

Approaching ball has…

Answer 13

Collision kinetic energy

Question 14

During impact the ball has…

Answer 14

Elastic potential energy

Question 15

A rebounding ball has…

Answer 15

Rebound kinetic energy

Question 16

Explain the coefficient of restitution

Answer 16

Measure of balls liveliness
Ratio of outgoing to incoming speed
Outgoing speed/incoming speed.

Question 17

During collision what dents?

Answer 17

The ball and the surface it hits

Question 18

The denting surface…

Answer 18

Stores and returns the energy, in a rebound effect.

Question 19

Explain moment of inertia

Answer 19

Axis goes through centre of gravity

Once airborne angular momentum doesn’t change because there is nothing to push or pull against

Question 20

How to divers manipulate moment of inertia?

Answer 20

Tucking, meaning mass is closer to the axis of rotation, less movement of inertia

Question 21

Define fluid mechanics

Answer 21

The study of forces that develop fluid or air.

Question 22

2 major fluid resistance are…

Answer 22

Drag or lift

Question 23

What happens when an object moves through a fluid?

Answer 23

Creates a disturbance to the fluid, the greater the fluid means the greater the transfer of energy from object to fluid.

Question 24

Define wave drag and what impacts have on it

Answer 24

The component of drag found from surroundings.
Relative velocity of the wave
Technique
Open water

Question 25

Define form drag and the effects had on it

Answer 25

The drag on a object due to the shape.
Cross sectional area
Velocity of the subject
Surface roughness
Shape of object

Question 26

Define surface drag and explain the impacts on it

Answer 26

Surface drag is caused by the friction of the fluid on the surface of an object.
Relative velocity of moving object
Relative roughness of surface of object
Viscosity of the fluid
Surface area of object

Question 27

Define characteristics of turbulent air flow

Answer 27

Small turbulent pockets
Less drag
Eg oval ball (torpedo)

Question 28

Define characteristics of laminar air flow

Answer 28

Large turbulent pocket
More drag
Eg ballon sized

Question 29

Environmental impacts of drag

Answer 29

High air density = low drag
High atmosphere pressure = high drag
High humidity = high drag

Question 30

Describe Bernoulli’s principle

Answer 30

Velocity is inversely proportional to pressure
High velocity = low pressure
Low velocity = high pressure