Biomechanics Definitions and Equations

Question 1

Definition: 1st Law of Inertia

Answer 1

a body will remain at rest or in constant motion unless acted upon by an external force

Question 2

Definition: 2nd Law of Acceleration

Answer 2

A force applied to an object will produce acceleration in the direction of the force, that is directly proportional to the size of the force and inversely proportional to its mass

Question 3

Equation: 2nd Law of Acceleration

Answer 3

Force = Mass x Acceleration

Question 4

Definition: 3rd Law of Action Reaction

Answer 4

For every action, there is an equal and opposite reaction

Question 5

Definition: Mass

Answer 5

The quantity of matter found within a particular body

Question 6

Definition: Inertia

Answer 6

the resistance of a body to change its state of motion

Question 7

Definition: Force

Answer 7

A push or pull acting on an object as a result of its interaction with another object

Question 8

Definition: Normal Force

Answer 8

The support force exerted by one stable object on another

Question 9

Definition: Applied Force

Answer 9

A force that is aplied to an object by a person or another object

Question 10

Definition: Friction Force

Answer 10

The force exerted by a surface as it moves across another

Question 11

Definition: Drag Force

Answer 11

A frictional force exerted on a moving object through air or water (air or water resistance)

Question 12

Definition: Gravitational Force

Answer 12

A gravitational force is the force of attraction between two objects or bodies

Question 13

Definition: Friction

Answer 13

Friction occurs when two objects come into contact with each other and it opposes motion

Question 14

Definition: Weight

Answer 14

The force exerted on an object by gravity and is directly proportial to its mass (not the same as body weight)

Question 15

Definition: Distance

Answer 15

The distance travelled from start to finish

Question 16

Definition: Displacement

Answer 16

The difference between the initial position and the final position of an object

Question 17

Definition: Angular Distance

Answer 17

Is the total of all angular changes that result from an object or body part angle bewteen the starting and finishing position

Question 18

Definition: Angular Displacement

Answer 18

Is the difference in degrees between the object or body part’s initial and final positions

Question 19

Definition: Speed

Answer 19

The rate of change in distance

Question 20

Equation: Speed

Answer 20

Speed = Distance / Time

Question 21

Definition: Velocity

Answer 21

The rate of change of displacement

Question 22

Equation: Velocity

Answer 22

Velocity = Displacement / Time

Question 23

Definition: Angular Speed

Answer 23

The rate of change in angular distance

Question 24

Equation: Angular Speed

Answer 24

Angular Speed = Angular Distance / Time

Question 25

Definition: Angular Velocity

Answer 25

The rate of change in angular displacement

Question 26

Equation: Angular Velocity

Answer 26

Angular Velocity = Angular Displacement / Time

Question 27

Definition: Acceleration

Answer 27

The rate of change of velocity

Question 28

Equation: Acceleration

Answer 28

Acceleration = Change in Velocity (final - initial) / Time

Question 29

Definition: Angular Acceleration

Answer 29

The rate of change of angular velocity

Question 30

Definition: Momentum

Answer 30

The motion pssessed by the moving body (amount of motion in an object)

Question 31

Equation: Momentum

Answer 31

Momentum = Mass x Velocity

Question 32

Definition: Force Summation

Answer 32

The sequential and coordinated movement of each body segment to produce maximum velocity

Question 33

Definition: Impulse

Answer 33

The change in momentum of an object

Question 34

Equation: Impulse

Answer 34

Impulse = Force x Time

Question 35

Definition: 1st law of angular motion

Answer 35

Angular momentum of a rotating body is constant unless acted upon by an external torque (rotation)

Question 36

Definition: 2nd law of angular motion

Answer 36

A torque applied to an object will cuase a change in angular motion in te directiom of the applied torque that is directly proportional to the size of the torque applied and inversely proportional to the moment of intertia

Question 37

Equation: 2nd law of angular motion

Answer 37

Torque = Mass x Angular Acceleration

Question 38

Definition: 3rd law angular motion

Answer 38

For ever torque (rotation) there is an equal and opposite torque

Question 39

Definition: Torque

Answer 39

A measure of the turning (rotational or eccentric) force applied to a body

Question 40

Definition: Angular Motion

Answer 40

Is movement around an axis (internal or external) caused by an eccentric force

Question 41

Equation: Angular Motion

Answer 41

Torque = Force x Moment Arm (where you apply the force)

Question 42

Definition: Angular Momentum

Answer 42

The quantity of rotation of a body around an axis

Question 43

Equation: Angular Momentum

Answer 43

Angular Momentum = Moment of Inertia (mass x radium^2) x Angular Velocity

Question 44

Definition: Moment of Inertia

Answer 44

A measure of an objects reluctance to rotate

Question 45

Equation: Moment of Inertia

Answer 45

Moment of Inertia = Mass x Radium^2

Question 46

Definition: Projectile

Answer 46

The motion that any object or body possesses when release into the air

Question 47

Definition: Equilibrium

Answer 47

When all forces are balanced

Question 48

Definition: Balance

Answer 48

The ability to maintain equilirbium while stationary (static) or while moving (dynamic)

Question 49

Definition: Stability

Answer 49

The resistance to the change (disruption) of equilibrium

Question 50

Definition: Centre of Gravity

Answer 50

The centre point of an object, about which all of its wieght is evenly distributed and balanced

Question 51

Definition: Line of Gravity

Answer 51

An imaginary line which passes thorugh the centre of gravity and continues down into the centrea of an objects base of support

Question 52

Definition: Base of Support

Answer 52

The area of an object that is in contact with the surface supporting it

Question 53

Definition: Lever

Answer 53

A lever is a simple machine that consists of a rigid beam that roates around a fixed point (axis)

Question 54

Definition: 1st Class Lever

Answer 54

A lever where the axis is located between the force and resistance and has a mechanical advantage = 1 and thus can be a force or speed amplifier

Question 55

Definition: 2nd Class Lever

Answer 55

A lever where the resistance arm is less than the force arm, that is, the resistance is acting closer to the axis than the force. The mechanical advantage is greater than one and has a mechanical advantage where it acts as a force amplifier

Question 56

Definition: 3rd Class Lever

Answer 56

A lever where the resistance arm is greater than the force arm, that is, the resistance is acting further from the axis than the force. The mechanical advantage is less than one therefore has a mechanical disadvantage and is a speed amplifier.

Question 57

Equation: Mechanical Advantage

Answer 57

Mechanical Advantage = Force Arm / Resistance Arm