1.3a biomechanics

Question 1

define newtons first law of motion (inertia)

Answer 1

a body continues in a STATE OF REST or UNIFORM VELOCITY unless acted upon by an EXTERNAL or UNBALANCED FORCE

Question 2

Define Newton’s Second law of motion : ACCELERATION

Answer 2

a body’s RATE OF CHANGE in MOMENTUM is PROPORTIONAL to the SIZE of the FORCE applied and acts in the SAME DIRECTION as the force applied

Question 3

Define Newton’s Third law of motion : REACTION

Answer 3

for every ACTION FORCE applied to a body there is an EQUAL and OPPOSITE reaction force

Question 4

What is the equation for VELOCITY ?

Answer 4

velocity = displacement / time taken

Question 5

What is the equation for MOMENTUM ?

Answer 5

momentum = mass x velocity

Question 6

What is the equation for ACCELERATION

Answer 6

acceleration = (final velocity - initial velocity) / time taken

Question 7

What is the equation for FORCE ?

Answer 7

force = mass x acceleration

Question 8

Define FORCE

Answer 8

a PUSH or PULL that ALTERS that state of motion of a body

Question 9

Define INTERTIA

Answer 9

the RESISTANCE of a body to CHANGE its state of motion, whether at rest or while moving

Question 10

Define VELOCITY

Answer 10

the RATE OF CHANGE in DISPLACEMENT

Question 11

Define MOMENTUM

Answer 11

the QUANTITY of MOTION possessed by a body

Question 12

Define ACCELERATION

Answer 12

the RATE OF CHANGE in VELOCITY

Question 13

Define WEIGHT

Answer 13

GRAVITATIONAL PULL that the earth exerts on the body - (N)

Question 14

Define REACTION

Answer 14

EQUAL AND OPPOSITE FORCE in response to the action force placed upon it

Question 15

Define FRICTION

Answer 15

the force that OPPOSES the motion of TWO SURFACES in contact

Question 16

Define AIR RESISTANCE

Answer 16

a force that OPPOSES the MOTION of a body TRAVELLING through the air

Question 17

What are LIMB KINEMATICS ?

Answer 17

study movement in relation to TIME AND SPACE
- white dots

Question 18

What are FORCE PLATES ?

Answer 18

measure ground reaction forces

Question 19

What are WIND TUNNELS ?

Answer 19

test aerodynamic efficiency
- measure air resistance

Question 20

Define CENTRE OF MASS

Answer 20

the point at which a body is BALANCED in ALL DIRECTIONS

Question 21

How do you increase stability ?

Answer 21

increase mass = increase inertia
decrease CoM
increase BoS
more central LoG

Question 22

Define LINE OF GRAVITY

Answer 22

imaginary line that extends from the COM downwards to the FLOOR

Question 23

What is a FIRST CLASS lever ?

Answer 23

effort - fulcrum - load

Question 24

What is a SECOND CLASS lever ?

Answer 24

effort - load - fulcrum

Question 25

What is a THIRD CLASS lever ?

Answer 25

load - effort - fulcrum

Question 26

What is the EFFORT ARM ?

Answer 26

distance from the FULCRUM to the EFFORT

Question 27

What is the LOAD ARM ?

Answer 27

distance from the LOAD to the FULCRUM

Question 28

What is MECHANICAL ADVANTAGE ?

Answer 28

SECOND CLASS effort arm is greater than the load arm large load / small effort slower

Question 29

What is MECHANICAL DISADVANTAGE ?

Answer 29

THIRD CLASS load arm is greater than effort arm small load / large effort faster

Question 30

What is an INTERNAL FORCE ?

Answer 30

generated by the CONTRACTION of SKELETAL MUSCLE

Question 31

INTERNAL FORCE : EXAMPLE

Answer 31

100m - contract rectus femoris - extend knee - drive away from the blocks

Question 32

What is an EXTERNAL FORCE ?

Answer 32

comes from OUTSIDE the body and acts upon it

Question 33

What are the 4 examples of EXTERNAL FORCES ?

Answer 33

weight reaction friction air resistance

Question 34

What are the 5 effects of FORCE ?

Answer 34

create motion accelerate a body decelerate a body changing the direction changing the shape