biomechanical principles

Question 1

stability

Answer 1

stability refers to the resistance to the disruption of equilibrium.

Question 2

balance

Answer 2

balance refers to the ability to control equilibrium.

Question 3

factors that affect stability

Answer 3

base of support, centre of gravity, body mass, friction.

Question 4

base of support

Answer 4

a base of support refers to the area of an object that is in contact with the surface supporting it.

Question 5

centre of gravity (COG)

Answer 5

centre of gravity refers to the central point of an object.

Question 6

friction

Answer 6

friction refers to two surfaces making contact with each other.

Question 7

static equilibrium

Answer 7

static equilibrium refers to a body that is not moving or rotating.

Question 8

dynamic

Answer 8

dynamic refers to a body that is moving with constant velocity.

Question 9

impacts of factors affecting stability

Answer 9

base of support
the greater the base of support, the greater the stability of an object

centre of gravity
the height of centre of gravity affects stability, lowering the centre of gravity increases stability

body mass
increased body mass results in increased stability

friction
increased friction results in increased stability

Question 10

line of gravity

Answer 10

when the line of gravity is moved to the edge of the base of support, stability decreases.

Question 11

levers

Answer 11

levers refer to a beam or rigid structure that rotates around a fixed point (axis).

Question 12

leverage

Answer 12

leverage refers to the action or advantage of using a a lever

Question 13

three components of a lever

Answer 13

axis, resistance, force

Question 14

first class levers

Answer 14

• axis is between the resistance and the force
• in the human body the muscles provide the force
• increasing the distance from the axis to the resistance icnreases the range of motion of the lever and the velocity of the movement
• no mechanical advantage
• e.g. seesaw, scissors, crow bar

Question 15

second class levers

Answer 15

• resistance is close to the axis than the force
• designed to generate great force to move a large resistance
• very few 2nd class levers in the body
• e.g. wheelbarrow

Question 16

third class levers

Answer 16

• force is closer to the axis than the resistance
• require greater force to remove resistance
• increase the range of motion and the speed of the lever
• e.g. catapult

Question 17

role of levers

Answer 17

• less effort to move a resistance
• increased range of motion
• increased angular speed

Question 18

lever strength

Answer 18

• using racquets, bats, clubs -> it extends anatomical levers (bones)
• the longer the level the greater the force required to rotate the lever
• longer levers generate faster velocities if the object is hit, kicked or struck
• long levers are harder to control