Biomechanics

Question 1

Scalar and Vector quantities

Answer 1

Scalar - Size
Vector - Size and direction

Question 2

Mass definition

Answer 2

The quality of matter the body possesses

Question 3

Weight definition

Answer 3

The gravitational force exerted on an object

Question 4

Distance and Displacement

Answer 4

Distance - the path the body takes to move from start to finish
Displacement - shortest distance in a straight line from start to finish

Question 5

Speed and Velocity

Answer 5

Speed = distance/time
Velocity = displacement/time

Question 6

Acceleration definition and equation

Answer 6

The rate of change of velocity
Change in velocity/time

Question 7

Momentum definition and equation

Answer 7

The product of the mass and velocity of an object
Mass x Velocity

Question 8

Weight equation

Answer 8

Mass x acceleration

Question 9

Difference between Vertical forces and Horizontal forces

Answer 9

Vertical forces - two bodies in contact with another, reaction force
Horizontal forces - two or more bodies are in contact with one another, frictional force (a force that acts in the opposite direction to the motion of a body travelling through the air)

Question 10

3 factors affecting friction

Answer 10

• surface characteristics
• the temperature of the surfaces
• the mass of the object

Question 11

What does a horizontal force depend on?

Answer 11

• the faster the velocity, more resistance
• the larger cross section, more air resistance
• the shape and surface characteristics

Question 12

How do forces act on the body during linear motion?

Answer 12

Friction force : forwards ->
Air resistance : backwards <-
Weight : downwards
Reaction force : upwards

Question 13

Net force

Answer 13

The resultant force after all other forces have been considered

Question 14

Newtons 3 laws of motion

Answer 14

1st law : Object will not change its motion until a force acts upon it
2nd law : acceleration
3rd law : equal and opposite directions of forces

Question 15

Impulse equation

Answer 15

Force x Time

Question 16

Torque

Answer 16

The rotational consequence of force (where you put finger to open door)

Question 17

Torque equation

Answer 17

Force x distance from fulcrum

Question 18

3 quantities of angular motion and conservation of angular momentum

Answer 18

Angular velocity
Angular acceleration
Moment of inertia

Question 19

Angular velocity

Answer 19

Rate of rotation of a body around its axes of rotation

Question 20

Angular acceleration

Answer 20

Rate of change of angular velocity

Question 21

Moment of inertia

Answer 21

Body’s reluctance to alter rate of rotation

Question 22

What affects drag force?

Answer 22

• the shape
• the surface
• reducing cross sectional area
• streamline

Question 23

The Bernoulli principle (discus example)

Answer 23

Where air molecules exert less pressure the faster they travel and more pressure the slower they travel

• Air tries move high to low pressure
• Angle of attack - if altered creates hydrofoil shape
• Air travels faster over top of discus
• Air travels further over the top of the discus
• This creates a low pressure on top of discus
• aerofoil shape

Question 24

Mechanical advantage of third-class lever operating at hip for long jumper

Answer 24

• mechanical advantage is so large ranges of movement can be moved quickly
• 3rd class levers have a faster range of movement
• flexing at hip gain forwards movement + jump further

Question 25

What is horizontal displacement?

Answer 25

Distance something has travelled

Question 26

3 factors affecting horizontal displacement

Answer 26

• angle of release
• speed of release
• height of release

Question 27

Parabolic curve definition

Answer 27

A curve with matching left and right sides

Question 28

Factors affecting flight paths (2)

Answer 28

• gravity
• air resistance

Question 29

1st law of newton

Answer 29

Inertia law
- moving constantly until force applied
- force applied by muscles
- performer continue in current state until another force applied

Question 30

2nd law of newton

Answer 30

Law of acceleration
- force = mass x acceleration
- mass is constant
- to accelerate u need more force
- force produced by muscle contractions
- ground reaction force produced
- greater the force greater the acceleration

Question 31

3rd law of motion

Answer 31

Law of action and reaction
- equal and opposite reaction
- athlete produce force into ground/onto object
- ground/object apply equal and opposite force back on athlete
Eg sprinter

Question 32

Factors affecting stability

Answer 32

• height of centre of mass
• area of base of support
• position of line of gravity
• body mass

Question 33

What is optimum angle of release?

Answer 33

45