KINE 3050: Torque & Force Movement

T = Fd, perpendicular

equation for torque

*Force & lever arm

*Focuses on the ___ distance

centric forces, linear, does

*Forces that act through an object's CENTER OF MASS

*Produces ___ movement

*Line of action ___ pass through center of mass

eccentric forces, angular, doesn't

*Forces that DON'T act through an object's CENTER OF MASS

*Produces ___ movement

*Line of action ___ pass through center of rotation

torque

Turning effect of an ECCENTRIC force

*Rotational effect of an eccentric force

torque, rotational, axis, joints

___ is the ___ effect of an ECCENTRIC force

*If object is doing this, it must be done about an ___

*Usually is one of our ___

moment arm

The perpendicular distance between axis and the line of action of the force applied

perpendicular, axis, line of action

Moment arm is the ___ distance between the ___ and the __ __ __ of the force applied

lever

*Rigid rod that is rotated about a fixed point or axis

*Simple machine

joint, bone

Levers in the human body usually are a ___ or the associated __ segments

*Primary purpose of (second blank)

external force, internal force, fulcrum/axis/pivot point

What are the 3 main components for a lever system?

external force, load, resistance

*Can be the WEIGHT of our bodies or external loads

*First component of lever system

internal force, effort, muscle force

*How WE move a load; put in amount of effort if we want to move the load

*Second component of levers

fulcrum, axis, pivot point

Often a JOINT in our bodies

*Third component of levers

1, opposite, middle

Class ___ lever

*Internal and external forces are on __ sides of the fulcrum

*Fulcrum is in the ___

class 2 lever

*Fulcrum & internal force are on OPPOSITE sides of external force

*Internal & external forces are on the SAME side of the fulcrum

*Distance from fulcrum is greater for the internal force

2, fulcrum, internal, external, same, internal

Class __ lever:

*__ & ___ force are on OPPOSITE sides of ___ force

*Internal & external force are on the ___ side of the fulcrum

*Distance from fulcrum is GREATER for the __ force

class 3 lever

*Fulcrum & external force on EITHER sides of internal force

*Distance between EXTERNAL force & fulcrum is GREATER

*Harder to move

3, fulcrum, external, internal, external, harder

Class __ lever:

*__ & ___ force are on EITHER sides of ___ force

*Distance from fulcrum is GREATER for the __ force

*___ to move

mechanical advantage

Ratio of the moment arm distance of the INTERNAL force to the moment arm distance of the external force

internal moment arm/external moment arm

What is the formula for mechanical advantage?

internal, external

You have mechanical ADVANTAGE if the ___ moment arm size is GREATER THAN the ___ moment arm size

external, internal

You have mechanical DISADVANTAGE if the ___ moment arm size is GREATER THAN the ___ moment arm size

3rd, disadvantaged

Most joint in the human body are __ class levers

*Frequently in mechanically ___ positions

3, lighter, longer, throw, run

Class __ lever BENEFITS:

*Able to move __ loads ___ distance

*Gives ability to ___ objects & __ fast

class 2

What lever class is a push up exercise?

2 multiple choice options

class 2

Which lever class is a calf raise exercise

2 multiple choice options

class 2

Which is the most mechanically ADVANTAGED lever system?

2 multiple choice options

it depends

Are class 1 lever system mechanically advantaged or mechanically disadvantaged

2 multiple choice options

torque, movement, tension

Muscles generate __ to cause ___ in humans

*Muscle actions create ___

moment arms

Since muscles aren't located directly on top of joints/axes they have ___ ___

muscle tension * muscle moment arms

Equation for torque at the JOINT that a muscles crosses

torque, rotate, joint axis

*Muscular ___ causes our limbs to __ about a ___ ___

force, bigger, 3rd

In calculating TORQUE, __ may be a ___ factor in humans where we have mostly ___ class levers

axis of rotation

point around which something rotates

center of mass

the point where the entire mass of an object is assumed to be concentrated

center of gravity

the point where mass is evenly distributed & where the force of GRAVITY acts

gravity, total body motion

Center of ___ helps to estimate __ __ __

anatomical, L2-L3, 55-57%

When standing stationary in ___ position, the center of gravity is near __-___ (roughly __-__% of height

forward, backward, sideways, up, down

What ways can the center of gravity move in the body (5)?

gravity, Newtons Laws of Motion

Center of ___ is the point on the body that follows __ __ __ __

stability, mobility, balance

What does the location of the center of GRAVITY play a role in?

change, rotational

Torque has a tendency to produce a __ in ___ motion

*Required to rotate an object

vector

Is torque a vector or a scalar

1 multiple choice option

positive

Is COUNTERCLOCKWISE torque positive or negative

1 multiple choice option

negative

Is CLOCKWISE torque positive or negative

1 multiple choice option

center of rotation

*Point or line about which an object TURNS

*Ex: Door hinge

rotation, greater

A force applied FAR from the center of __ produces a ___ torque than a force applied CLOSE to the center of rotation

rotation, lesser

A force applied CLOSE from the center of __ produces a ___ torque than a force applied FAR to the center of rotation

torque, doesn't, rotation

___ is created when the line of action ___ pass through the center of ___

line of action

*Imaginary line of INDEFINITE LENGTH drawn along the direction of the force

small, more, torque, larger

A muscle w/ a __ moment arm needs to produce __ force to generate the same ___ as a muscle w/ a ___ moment arm

general, series, torques & rotations

Human motion is ___, but it's generated by a ___ of ___ & ___

no

Does the LINE OF ACTION of MUSCLE forces pass through the joints' axes of rotation?

1 multiple choice option

moment arms, shortest, perpendicular, axis

___ __:

*___ distance from force's line of action to axis of rotation

*Always ___ to line of action & passes through the __ of rotation

magnitude, moment arm, ROM

The ___ of the __ __ of the biceps muscle CHANGES throughout the ___

moment arm, distance, force, angle

The ___ ___ is determined by the ___ from axis of rotation at which ___ is applied & the __ at which force is applied

perpendicular, line of action, rotation

Moment arm is ALWAYS ___ distance between __ __ __ of the force & center of __

mass, imaginary, physical, fixed

The center of __ is an ___ point in space

*NOT a ___ entity or a ___ point

mass, position

Center of __ changes when parts of an object change ___

downward

How does the FORCE OF GRAVITY act through the center of MASS?

line of gravity

imaginary vertical line from center of gravity to ground surface

base of support

Area within the perimeter of each point of contact w/ the ground

stability

*Resistance to disruption of equilibrium

*Likelihood of an object to return to its ORIGINAL position after displacement

balance, agility

Ability to CONTROL equilibrium

*Important part of ___

resistance, return, original, controlling

Stability focuses on the ___ to disrupt equilibrium & ability to ___ to its ___ position, while balance focuses on ___ equilibrium

equilibrium, gravity, force, gravity, support, line

Stability affecting Factors:

*State of ___: balanced/forces equal

*___: attraction between earth & object

*Gravitational ___: directed vertically downward

*Center of ___: balance point of object

*Base of ___: part of body contact w/ support surface

*___ of gravity

direct

What is the relationship between mass & stability?

1 multiple choice option

direct

What is the relationship between AREA of base & stability?

1 multiple choice option

direct

What is the relationship between WEIGHT of body & stability?

1 multiple choice option

inverse

What is the relationship between DISTANCE of body above base & stability?

1 multiple choice option

stability, directly, horizontal, gravity, base, movement

__ is ___ proportional to ___ distance of the center of ___ from the edge of the __ toward given direction of ___

stability, gravity, balance, equal, all

For ___, the center of ___ needs to be a ___ point with TORQUE __ on __ sides

vertically downward

What is the direction of gravitational force need to be to have stability?

torque, rotation, axis

The outcome of __ is to produce a __ about an ___

lever, rigid, rotate, axis, fulcrum

A __ is a simple machine consisting of a ___ bar-like body that can be made to __ about an __ or __

force position, applied force, resistance, fulcrum

What are the 4 things that classify a LEVER?

interaction, internal & external

The __ between ___ & ___ forces ultimately CONTROLS MOVEMENT

levers, pivot point, rotation, joint

Internal & external forces interact through a system of bony ___, with the ___ __ located at the axis of ___ of our ___

levers, torques, movement, joints

Through a system of ___, forces are converted to __, and causes ___ of our ___

power, distance, not

A lever will EITHER favor __ or ___, but __ both

inverse

What is the relationship between power & distance?

1 multiple choice option

axis, force, resistance, type

Arrangement of the ___ in relation to the ___ and the __ determines the __ of lever

easier, greater distance

When FULCRUM arm is LONGER, the part will be ___ to move, but will have to move a ___ ___

harder, less distance

When RESISTANCE/LOAD arm is LONGER, the part will be ___ to move, but will have to move a ___ ___

teeter-totter, car jack, crowbar

What are (3) examples of first class levers

first, loads, effort

__ class levers are useful for lifting LARGE __ w/ LITTLE ___

wheelbarrow, bottle opener, oar

What are (3) examples of second class levers

second, distance

___ class levers makes it easier to move objects over ___

tweezers, baseball bat swing, lifting with arms

What are (3) examples of third class levers

third, precise

___ class levers are good at making ___ movements

fulcrum

In a FIRST class lever, what is located in the MIDDLE

*What is the "between" component

2 multiple choice options

load

In a SECOND class lever, what is located in the MIDDLE

*What is the "between" component

2 multiple choice options

effort

In a THIRD class lever, what is located in the MIDDLE

*What is the "between" component

2 multiple choice options

direct

What is the relationship between mass/inertia & stability

lower, potential, work

*When the CoG is ___, stability INCREASES

*Most stable position is one that MINIMIZES ___ energy

*Moving to another position requires __

equilibrium, equal

___ is a state of BALANCE where all forces & torques are ___

magnitude, direction & location

Torque is determined by ___, ___ & ___

*Remember it is a VECTOR

no

Can you still rotate an object WITHOUT torque?

1 multiple choice option

force

What is the action that creates changes in LINEAR motion?

force, where, point, rotates

Torque is created by ___

*Depends on:

*___ force is applied

*___ where the object ___