UNIT 2 (biomechanical principles)

Question 1

what is force

Answer 1

a push or pull movement that alters the state of motion of a body

Question 2

what can a force cause to happen to a body

Answer 2

change direction
accelerate
decelerate
change an objects shape

Question 3

what are the units for force, mass and acceleration

Answer 3

newtons (N)
kilograms (KG)
meters per second squared m/s^2

Question 4

what are internal forces

Answer 4

forces produced by concentric muscle contraction

Question 5

what are external forces

Answer 5

things such as gravity, air/water resistance, friction and ground reaction force

Question 6

what are the types of motion

Answer 6

linear, angular and general

Question 7

what is linear motion

Answer 7

motion in a straight line which all body parts moving the same distance at the same speed in the same direction

Question 8

what is angular motion

Answer 8

circular movement around a fixed point/ axis

Question 9

what Is general motion

Answer 9

movements which are a combination of linear and angular motion

Question 10

what are the 3 laws of motion

Answer 10

law of inertia
law of acceleration
law of action and reaction

Question 11

what is the law of inertia

Answer 11

an object will remain at rest or in motion in a straight line until acted on upon an external force

Question 12

what is the law of acceleration

Answer 12

F=MA
acceleration is directly proportional to force applied and inversely proportional to the mass.

Question 13

what is the law of action and reaction

Answer 13

for every action there is an equal and opposite reaction.

Question 14

what is the equation for distance

Answer 14

Distance=speed x time

Question 15

if a force is applied through the middle of an object (through centre of mass), what type of motion will it have

Answer 15

linear motion

Question 16

if a force is applied off the centre of mass what type of motion will the object have

Answer 16

angular motion

Question 17

what is momentum

Answer 17

a quantity of motion, it is a product of Mass and velocity.

Question 18

what is velocity

Answer 18

it is the speed something is moving in a direction

Question 19

what is impulse

Answer 19

the product of force and time it takes to apply the force.

Question 20

impulse equation

Answer 20

impulse=force x time

Question 21

what is net impulse

Answer 21

overall change in momentum of an object. it is the positive impulse - negative impulse

Question 22

when does positive impulse occur

Answer 22

when force is applied in the same direction of motion, this will increase its velocity

Question 23

when does negative impulse occur

Answer 23

when a force is applied in the opposite direction of motion, this will decrease its velocity

Question 24

how does impulse affect momentum

Answer 24

a overall positive impulse will increase momentum as it increases the velocity.
an overall negative impulse will decrease momentum because it decreases velocity

Question 25

how can a performer increase impulse

Answer 25

-increase the force applied -increase the time force is applied for -combining both force and time

Question 26

how an a hammer thrower increase the impulse

Answer 26

apply a greater force by moving the arm faster therefore becoming stronger. OR apply the force for longer by spinning and releasing the hammer at the last moment.

Question 27

what is stability

Answer 27

the ability of a body to return to equilibrium after being displaced

Question 28

what is centre of mass

Answer 28

the point at which the body is balanced in all direction

Question 29

what can centre of mass also be called

Answer 29

centre of gravity

Question 30

what is the line of gravity

Answer 30

imaginary line which passes vertically from the centre gravity to the ground below the object

Question 31

is an object with a larger base of support more stable or less stable?

Answer 31

more stable

Question 32

what factors effect stability

Answer 32

mass of object size of base of support height of centre of mass points of contact

Question 33

how does the mass of an object effect stability

Answer 33

heavier objects have a greater stability because there inertia is greater.

Question 34

how does size of base of support effect stability

Answer 34

a larger base of support increases stability because it allows the centre of mass to remain in the area more easily

Question 35

how does height of the centre of mass effect stability

Answer 35

lower centre of mass enhances stability because the closer the centre of mass to the ground the less leverage there is for forces to move it outside the base of support

Question 36

how does the number of contacts with the floor increase stability

Answer 36

more points of contact increases stability because it increases their base of support.