Week 2: Kinetics

Question 1

What is the term for the displacement of a body or one of it’s segments from one point to another?

Answer 1

Motion

Question 2

Linear motion is also known as what type of motion?

Answer 2

Translational Motion

Question 3

Movement around an axis is known as this type of motion?

Answer 3

Rotational Motion

Question 4

Movement around joints is usually what kind of motion?

Answer 4

Rotational

Question 5

True or False: Movement is a combination of rotational and translational?

Answer 5

True

Question 6

Linear or Translational Motion is measured in what?

Answer 6

Meters AND/OR feet per second

Question 7

Rotational Motion is measured in what?

Answer 7

Degrees (for ROM) per second

Question 8

What is the term for the distance that a force moves a body?

Answer 8

Magnitude

Question 9

True or False: Direction of motion cannot be positive and negative

Answer 9

False

Question 10

What is the term for the rate at which the body or segments move?

Answer 10

Velocity

Question 11

What is the term for a push or pull that produces displacement?

Answer 11

Force

Question 12

What is the term for the motion of a body or segment that occurs when force is applied?

Answer 12

Displacement

Question 13

What is the term for when a system is in balance?

Answer 13

Equilibrium

Question 14

What is the term for the amount of matter contained within an object?

Answer 14

Mass

Question 15

True or False: Mass is a variable amount

Answer 15

False, it is constant

Question 16

What is the term for the force of gravity on an object which changes depending on gravitational pull?

Answer 16

Weight

Question 17

What is the term for the elements that produce force on bone segments by active contraction and passive stretching?

Answer 17

Muscles

Question 18

Four primary forces?

Answer 18

1. Gravity
2. Muscles
3. Externally Applied Resistance
4. Friction

Question 19

What is the result of force acting at a distance from the point of motion or the axis

Answer 19

Moment

Question 20

What is the moment equation?

Answer 20

Moment = distance x force

Question 21

What is the force equation?

Answer 21

Force = mass of an object x acceleration of an object

Question 22

2 elements that help express “force”?

Answer 22

1. Magnitude

2. Rate of change

Question 23

Law of Inertia/Equilibrium?

Answer 23

Newton’s Law (Law #1) that states that a body at rest will remain at rest and a body in motion will stay in motion until an outside force acts upon it

Question 24

Newton’s second law of motion?

Answer 24

The acceleration of a body is proportionate to the magnitude of the forces acting on it and inversely proportionate to the mass of the body
–> a greater force is required to move a larger mass

Question 25

Newton's third law of motion?

Answer 25

For every action force there is an equal and opposite reaction force

Question 26

What is the term for a simple machine consisting of a rigid bar that rotates around a fulcrum or axis?

Answer 26

Lever

Question 27

3 elements of mechanical levers?

Answer 27

1. Axis 2. Resistance Arm (RA) 3. Force Arm (FA)

Question 28

First class lever?

Answer 28

Axis is in the middle of the FA and RA

Question 29

Second class lever?

Answer 29

The RA lies between the axis and the FA; the RA is always closer to the axis than the FA

Question 30

Why does the RA have the advantage in a second class lever?

Answer 30

Because with its location closer to the axis, larger weights can be moved using smaller amount of force

Question 31

Third class lever?

Answer 31

The FA lies between the axis and RA; the RA is longer than the FA so it has the advantage

Question 32

What's the most common lever type in the body?

Answer 32

Third

Question 33

What is the equation for calculating mechanical advantage?

Answer 33

Force Arm length/Resistance Arm length

Question 34

What is mechanical advantage?

Answer 34

the ability to counter resistive forces in a lever system

Question 35

FA>RA

Answer 35

greater than 1 | 2nd class

Question 36

FA

Answer 36

less than 1 | 3rd class

Question 37

FA=RA

Answer 37

equal | 1st class

Question 38

What is torque?

Answer 38

The rotary force around an axis

Question 39

True or False: Torque is greater near the axis; as opposed to further out?

Answer 39

False; Torque is greater further out

Question 40

True or False: if torque is the same, force required near the axis is greater than further out?

Answer 40

True

Question 41

What's the term for the point where the mass of the body is equally distributed; it is constantly changing?

Answer 41

Center of Mass (COM)

Question 42

What's the term for the direction where the mass of the body is equally distributed against gravity; this cannot be controlled

Answer 42

Center of Gravity (COG)

Question 43

What's the term for the area that has the greatest amount of stability within the body?

Answer 43

Base of Support

Question 44

For the greatest amount of stability, what two things must be close to one another?

Answer 44

COG and BOS

Question 45

With regards to levers, what is the resistance force?

Answer 45

Weight

Question 46

With regards to levers, what is the force arm refer to?

Answer 46

Moving force