Biomechanics

Question 1

Newtons laws

Answer 1

1st - object continue in state of constant velocity until compelled by external force

2nd - f=ma

3rd -for every action there’s and equal and opposite reaction.

Question 2

Centre of mass

Answer 2

Point in the object where mass is distributed evenly

Factors affecting the COM
-distribution (leaning)

Stability
- higher COM less stable
- greater mass more stable
- base support , broader more stable

Question 3

Levers

Answer 3

Class 1 - F in middle , elbow extension

Class 2 - R in middle , tip toes

Class 3 - E in middle , elbow flexion

Question 4

Mechanical advantages

Answer 4

Longer effort arm

• overcome heavy loads
• 2nd class
• although shorter ROM and SOC

Question 5

Mechanical advantages

Answer 5

Longer effort arm

• overcome heavy loads
• 2nd class
• although shorter ROM and SOC

Question 6

Mechanical advantages and disadvantages

Answer 6

Mechanical advantage

Long Effort arm - distance between effort and fulcrum , class 2 , large loads overcome with little effort

Short resistance arm - class 2 , narrow ROM

Mechanical disadvantage

Long resistance arm - 1st class and all of class 3 , large ROM

Short effort arm - faster movement

Question 7

Vectors and scalars

Answer 7

Vector - magnitude and direction

Velocity
Force
Weight
Momentum
Displacement

Scalar - magnitude quantity

Distance
Speed
Mass

Question 8

Horizontal forces

Answer 8

Air resistance
Friction

F=AR = constant velocity

Question 9

Vertical forces

Answer 9

Weight
Ground reaction force - force exerted onto the ground

Question 10

Impulse

Answer 10

When two objects collide

Size of force reaction - higher will see more impulse

Time that force is applied for - follow through will increase impulse

Force x time = impulse

More velocity
More momentum

Ways to reduce impulse

Cushioning
Crash mats

Question 11

Newton analagoues

Answer 11

N1- constant state of angular momentum until external torque acts

N2- angular acceleration is proportional to the force acting

N3- an object will always apply a reaction torque proportional in size but opposite in direction

Torque = rotational force

Question 12

Angular motion

Answer 12

Force goes away from COM causing AM and a ball to spin

Question 13

Angular momentum

Answer 13

Body constant angular momentum unless external force acts upon it

AM= AV x inertia

It’s constant