Biomechanics - 8 - Statics Analysis

statics

______ is the study of systems in equilibrium where forces acting on the system are balanced

point of application

with force vectors, the base of the arrow represents the ___________

action line and direction

with force vectors, the shaft and arrowhead represent the _________________

magnitude 

with force vectors, the length of the arrow represents the _____________

composition of vectors

_____________ is the addition of coplanar forces that can be illustrated graphically

T

T/F: composition of vectors can be accomplished by first mathematically resolving forces into horizontal and vertical components

commutative

the addition of vectors follows a __________ property

you always end up with the same answer no matter the order of addition

the commutative property of vector addition is important because: 

resolution

________ of vectors is when force vectors are split into horizontal and vertical components

composition

_________ of vectors is when force vectors are added together

free body diagrams

______________ are simple ways to indicate force systems with arrows and bars

lever arm 

the _________ is defined as the distance from the axis of rotation to the point of the applied load 

moment arm

the __________ is defined as the perpendicular distance from the line of action to the axis of rotation

moment

the (lever/moment) arm changes with movement

lever

the (lever/moment) arm is constant regardless of positional changes

57

muscles can shorten ___% of their resting length 

mechanical advantage, excursion disadvantage

second class levers:

• mechanical (advantage/disadvantage)

• excursion (advantage/disadvantage)

mechanical disadvantage, excursion advantage

third class levers:

• mechanical (advantage/disadvantage)

• excursion (advantage/disadvantage)

F; torque DOES change with position

T/F: if a moment arm of a constant load changes with position, then torque produced by an external load does not change with position

T

T/F: if a moment arm of muscle changes with position, then the force required by muscle changes with position.

*check the slides and notes for lots of diagrams and examples*

*check the slides and notes for lots of diagrams and examples*