#3.5 u3aos1 - equilibrium and human movement

Question 1

equilibrium
2 marks

Answer 1

the state of motion, whether at constant motion or rest
where all forces and torque are balanced

Question 2

stability
1 mark

Answer 2

the body’s ability to resist change in a current state

Question 3

balance
1 mark

Answer 3

body’s ability to control and maintain equilibrium

Question 4

two types of equilibrium
2 marks

Answer 4

static equilibirium
dynamic equilibrium

Question 5

static equilibrium
1 mark

Answer 5

an object or body must be completely motionless

Question 6

three conditions of static equilibrium
3 marks

Answer 6

1. sum of all vertical forces on body must equal to 0
2. sum of all horizontal forces on body must equal to 0
3. sum of all torques must be equal to 0

Question 7

dynamic equilibrium
2 marks

Answer 7

when an object or body is moving with constant velocity
with no change in direction or speed

Question 8

five factors that effect stability
5 marks

Answer 8

• body mass
• friction
• line of gravity
• centre of gravity
• base of support

Question 9

base of support
1 mark

Answer 9

the outside edges of the body that comes in contact with a supporting surface

Question 10

how to increase base of support
3 marks

Answer 10

larger base of support = more stability on an object
- moving one foot forward = stability forwards and backwards
- moving one foot away from midline = stability side to side

Question 11

centre of gravity
1 mark

Answer 11

point at which weight is balanced, regardless of the position of the body

Question 12

when is stability increased in temrs of centre of gravity
1 mark

Answer 12

when centre of gravity is lowered

Question 13

line of gravity
2 marks

Answer 13

theoretical line that passes through the centre of gravity
in the direction gravity acts

Question 14

when is stability increased in terms of line of gravity
1 mark

Answer 14

when line of gravity is within the base of support

Question 15

how is stability effected in terms of body mass
2 marks

Answer 15

greater mass -> greater force required to act on it = harder to disrupt equilibrium
lower mass -> less force required to act on it = easier to disrupt equilibrium

Question 16

friction
1 mark

Answer 16

the interaction between two objects or bodies in the opposite direction

Question 17

how is stability effected in temrs of friction
2 marks

Answer 17

increased friction between body and surface of contact = increased stability
decreased friction between body and surface of contact = decreases stability

Question 18

levers
2 marks

Answer 18

a simple machine consisting of a rigid bar
that can be made to rotate around an axis

Question 19

three components of a lever
3 marks

Answer 19

axis
resistance
force

Question 20

1st class lever
1 mark

Answer 20

where the axis is in the middle
of the force and resistance

Question 21

2nd class lever
1 mark

Answer 21

where the resistance is in the middle of the force and axis

Question 22

3rd class lever
4 mark

Answer 22

where the force is in the middle of the axis and resistance
requires a greater force to change resistance
focuses on speed and range of motion
mechanical advantage will always be <1

Question 23

mechanical advantage formula
1 mark

Answer 23

mechanical advantage = force/resistance

Question 24

characteristics of mechanical advantages being <1
3 marks

Answer 24

• greater force required over a short period of time
• increased range of motion
• increased angular speed

Question 25

what does increasing the lever length do.
2 marks

Answer 25

• increase in distance from axis to the resistance = resistance arm is longer than force arm
• greater force will be required to swing the bat = increased velocity translates to the ball