4.3 Biomechanics

Question 1

Define Biomechanics

Answer 1

Biomechanics: application of mechanical principles (force & motion) related to the human body and sporting implements

Question 2

What mathematical measures are used to measure biomechanics?

Answer 2

Scalers & Vectors

1. scalar quantity - has only magnitude (size)
2. vector quantity - has both magnitude and direction

Question 3

Define the terms force, speed, velocity, displacement, acceleration, momentum and impulse.

3.1

Answer 3

force - push or pull upon an object resulting from the object’s interaction with another object

speed - the rate at which an object covers distance

velocity - change in displacement divided by the time taken for the change to take place

displacement - the difference between an object’s final position and it’s starting position

acceleration - the rate of change of velocity per unit of time

momentum - the quantity of motion of a moving body, measured as a product of its mass and velocity

impulse - change of momentum of an object when the object is acted upon by a force for an interval of time

Question 4

Explain the relationship between distance and direction.

Answer 4

Distance does not depend on direction.

Displacement is the difference between an object’s final position and it’s starting position. Displacement does depend on direction.

Question 5

How do speed and velocity differ?

Answer 5

speed: how fast you are travelling
velocity: how fast (speed) you are travelling in a given direction (vector quantity)

E.g.
Speed of 10m/s
Velocity of 10m/s east

Question 6

What is the formula of velocity?

Answer 6

Question 7

What is the formula of acceleration?

Answer 7

change in velocity: final velocity - initial velocity
change in time: finish time - start time

Question 8

What are the formulas for: speed, direction & time?

Answer 8

Question 9

Analyse velocity (speed)–time graphs of sporting actions.

3.2

Answer 9

Velocity-time graphs: illustrate how an object’s speed changes over time.
* The steeper the gradient of the line, the greater the acceleration.
* can look simialr to speed-time graphs, velocity-time graphs can have negative values + direction

Question 10

What is the difference between a velocity–time graph and a speed-time graph?

3.2

Answer 10

• velocity graphs need a direction
• speed graphs have only positive values, velocity can also have negative values

Question 11

What do ____ mean on velocity-time graphs?

1. positive slopes
2. horizontal lines
3. negative sloped
4. curved slope

3.2

Answer 11

1. positive slopes: speed increasing/object accelerating
2. horizontal lines: travelling at constant speed
3. negative slopes: speed decreasing/negative acceleration
4. curved slope: acceleration changing/non-uniform acceleration

Question 12

Analyse distance–time graphs of sporting actions.

3.2

Answer 12

Question 13

What do ____ mean on distance-time graphs?

1. positive slopes
2. horizontal lines
3. negative sloped
4. curved slope

3.2

Answer 13

Question 14

Analyse force–time graphs of sporting actions.

3.2

Question 15

Define the term centre of mass.

3.3

Answer 15

centre of mass - mathematical point around which the mass of a body or object is evenly distributed

the lower the centre of mass of an object the more stable it is

Question 16

Explain that a change in body position during sporting activities can change the position of the centre of mass.

3.4

Question 17

Distinguish between first, second and third class levers.

3.5

Question 18

Label anatomical representations of levers

3.6

Question 19

Define Newton’s three laws of motion.

3.7

Question 20

What do Newton’s 3 laws of motion cover?
What are they called?

3.7

Answer 20

“Newton’s laws of motion are three physical laws that together laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to said forces”.

Law 1:
The Law of Inertia

Law 2:
The Law of Acceleration

Law 3:
The Law of Action/Reaction

Question 21

What do Newton’s 3 laws of motion cover?
What are they called?

3.7

Answer 21

“Newton’s laws of motion are three physical laws that together laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to said forces”.

Law 1:
The Law of Inertia

Law 2:
The Law of Acceleration

Law 3:
The Law of Action/Reaction

Question 22

Explain how Newton’s three laws of motion apply to sporting activities.

3.8

Question 23

State the relationship between angular momentum, moment of inertia and angular velocity.

3.9

Question 24

Explain the concept of angular momentum in relation to sporting activities.

3.10

Question 25

Explain the factors that affect projectile motion at take-off or release.

3.11

Question 26

Outline the Bernoulli principle with respect to projectile motion in sporting activities.

3.12