Biomechanics

Question 1

What are newtons 3 laws of linear motion ?

Answer 1

• Law of inertia
• Law of accelaration
• Law of action and reaction

Question 2

What is the law of inertia ?

Answer 2

this is where a performer will remain still until a force has been applied

Question 3

What is the law of acceleration ?

Answer 3

force= mass* acceleration

Question 4

What is the law of action and reaction ?

Answer 4

for every action there is an equal and opposite reaction

Question 5

What is an example for a first class lever ?

Answer 5

triceps extending in the elbow

Question 6

What is an example of a second class lever ?

Answer 6

plantarflexion of the ankle

Question 7

What is the mechanical advantage of a first and third class lever ?

Answer 7

large range of movement and quick resistance

Question 8

What is the mechanical advantage of a second class lever ?

Answer 8

can generate much larger forces, as it has to lift the whole body

Question 9

What is mechanical disadvantage of first and third class lever ?

Answer 9

cannot apply much force to move an object

Question 10

What is mechanical disadvantage of second class lever ?

Answer 10

slow, with a limited range of movement

Question 11

What is a scalar quantity ?

Answer 11

these are quantities that just have size

Question 12

What are vector quantities ?

Answer 12

theses are quantities that have size and direction

Question 13

What are 3 examples of a scalar quantity ?

Answer 13

• Speed
• Mass
• Distance

Question 14

What are 3 examples of a vector quantity ?

Answer 14

• velocity
• weight
• acceleration

Question 15

What is the conversation of momentum ?

Answer 15

this occurs when a athlete is in flight. When in flight neither mass or velocity can be altered. Mass is always constant.

Question 16

What are internal forces ?

Answer 16

these are forces generated by muscular-skeletal system

Question 17

What are external forces ?

Answer 17

forces from outside of the body

Question 18

What are two types of external forces ?

Answer 18

• horizontal forces
• vertical forces

Question 19

What are two examples of horizontal forces ?

Answer 19

• friction
• air resistance

Question 20

What are two examples of vertical forces ?

Answer 20

• weight
• reaction force

Question 21

What is a balanced force ?

Answer 21

this is when there are two or more forces acting on a body that are equal in size but opposite in direction

Question 22

What is a unbalanced force ?

Answer 22

this is created when a force acting in one direction is larger than the force acting in the opposite direction

Question 23

What is impulse ?

Answer 23

this is the time taken for a force to be applied

Question 24

How do you calculate impulse ?

Answer 24

Impulse= force*time

Question 25

When does angular motion occur ?

Answer 25

when a force is applied outside of the centre of mass

Question 26

What is torque ?

Answer 26

this is a turning force

Question 27

What are the 2 things that torque is dependant on ?

Answer 27

• the greater the size of the force the greater the torque
• application of the same force further away from the axis will increase torque

Question 28

How do you calculate moment of force ?

Answer 28

force*perpendicular distance from the fulcrum

Question 29

How does an athlete reach equilibrium ?

Answer 29

the sum of the clockwise movements must be equal to the sum of the anticlockwise movements about the fulcrum

Question 30

What is angular displacement ?

Answer 30

this is the smallest change in angle between the starting point and the finishing point.

Question 31

What is angular displacement measured in ?

Answer 31

radians

Question 32

What is 1 radian in degrees ?

Answer 32

1 radian = 57.3 degrees

Question 33

What is angular accelaration ?

Answer 33

this is the rate of change of angular velocity

Question 34

How is angular velocity calculated ?

Answer 34

angular displacement/time taken

Question 35

How is angular acceleration calculated ?

Answer 35

change in angular velocity/time taken

Question 36

What is inertia ?

Answer 36

the resistance of the body to change in motion

Question 37

What is moment of inertia ?

Answer 37

the resistance of the body to change in motion when rotating

Question 38

What 2 factors is moment of inertia dependant on ?

Answer 38

• the mass of the object. The greater the mass the greater resistance to change and therefore the greater the moment of inertia
• how the mass is distributed from the point of rotation. The further the mass from the point of rotation =the bigger the momentum of inertia and the harder to stop the movement,

Question 39

How is angular momentum calculated ?

Answer 39

angular velocity*moment of inertia

Question 40

Is angular momentum conserved ?

Answer 40

yes

Question 41

What relationship does angular momentum have with moment of inertia

Answer 41

they have a inversely proportional relationship. If one decreases the other increases

Question 42

What is the conversation of angular momentum ?

Answer 42

a body will keep on spinning/rotating unless forces act upon it

Question 43

What is projectile motion ?

Answer 43

this refers to the movement of an object in flight.

Question 44

What are the 3 factors that affect horizontal displacement of an object ?

Answer 44

• angle of release. The optimum angle of release is dependant upon release height and landing height
• velocity of release. The greater the release of the velocity of a projectile the greater the horizontal displacement.
• height of release. the greater the height of the release of an object the greater the horizontal displacement.

Question 45

What are the two types of projectile ?

Answer 45

• parabolic projectile
• distorted projectile