Test Three system as a machine

Question 1

machine

Answer 1

an apparatus/system that uses the combined action of several parts in order to apply mechanical force

Question 2

what part of the body can technically be classified as an intrinsic machine

Answer 2

joint

Question 3

what the three types of machines in the human body

Answer 3

lever systems, wheel and axis systems, pulley systems

Question 4

machines function

Answer 4

transmit a force, increase the magnitude of a force, increase the linear distance and velocity of a force, change the direction of a force

Question 5

example of transmit force

Answer 5

tendons transmit muscle forces to bones

Question 6

example of increase the magnitude of a force

Answer 6

less effort required to move a given resistance

Question 7

example of increase the linear distance and velocity of a force

Answer 7

a resistance is moved a greater distance or at a faster rate than the motive force

Question 8

example of change the direction of a force

Answer 8

a resistance is moved in a different direction that that of the motive force

Question 9

lever system

Answer 9

consists of a rigid or semi-rigid object (lever) that is capable of rotating about an axis (fulcrum)

Question 10

purpose of lever system

Answer 10

to transmit energy from one place to another

Question 11

what is needed to produce the torque necessary to rotate the lever

Answer 11

fulcrum placed on axis of rotation, force must be off-axis

Question 12

what are the two types of torque in a lever system

Answer 12

motive torque and resistive torque

Question 13

what is a motive torque

Answer 13

an eccentrically applied force that attempts to rotate the lever in one direction about the fulcrum

Question 14

what is a resistive torque

Answer 14

an eccentrically applied force that attempts to rotate the lever in the opposite direction

Question 15

what are the parts needed to form a lever system

Answer 15

rigid lever, fulcrum, motive torque and resistive torque

Question 16

example of rigid lever

Answer 16

bones

Question 17

example of fulcrum

Answer 17

joints

Question 18

example of motive torque

Answer 18

muscles

Question 19

example of resistive torque

Answer 19

weight of segment

Question 20

mechanical advantage

Answer 20

the relationship of the motive force to a given resistive force

Question 21

example of mechanical advantage

Answer 21

the amount of one required to overcome the other

Question 22

what causes variation with the system of mechanical advantage

Answer 22

based on the location of the fulcrum

Question 23

as fulcrum placement changes, the relative lengths of the

Answer 23

moment arms for the motive and resistive forces varies

Question 24

if fulcrum is in middle what happens with resistive or motive force

Answer 24

they dont have an advantage due to the moment arms are the same length

Question 25

if the fulcrum is moved farther away from the motive force

Answer 25

then its moment arm becomes longer and gains a mechanical advantage, gain in force production

Question 26

if the fulcrum is closer to the motive force

Answer 26

then the moment arm for the resistive force becomes longer, and the resistive force has the advantage, gain in linear distance and velocity

Question 27

three types of lever systems

Answer 27

first, second and third

Question 28

first class lever

Answer 28

one in which the fulcrum is between the motive and resistive force, balance two forces

Question 29

which lever system is the most versatile

Answer 29

first class

Question 30

how can the first class lever be capable of creating an advantage in force

Answer 30

the fulcrum can be moved farther from the applied motive fore

Question 31

since the resistive end travels a greater linear distance in the same time of the first class lever, the resistive end of the lever also has

Answer 31

a greater linear velocity

Question 32

the first class lever system is being used

Answer 32

to gain an advantage in linear range of motion and velocity

Question 33

final function of a machine is to

Answer 33

change the effective direction of an applied force

Question 34

second class lever system

Answer 34

the resistive force is between the fulcrum and motive force

Question 35

what are the implications of the second class lever

Answer 35

the moment arm for the motive force will always be greater than the moment arm of the resistive force

Question 36

levers of the second class are always used

Answer 36

to gain an advantage in force production

Question 37

short moment arm for resistive force in second class

Answer 37

linear distance traveled is small relative to motive end, no advantage in linear range of motion and velocity gained

Question 38

second lever, resistance is moved in the

Answer 38

same direction as the applied force, cant be used to change the effective direction of the applied force, or balance two forces

Question 39

third class lever

Answer 39

the motive force is between fulcrum and resistive force

Question 40

implications of third class lever

Answer 40

the moment arm for the motive force will always be less than the moment arm of the resistive force

Question 41

third class levers are used for

Answer 41

to gain advantage in linear range of motion and velocity

Question 42

third class lever has short moment arm for motive force so

Answer 42

a dispropotionately large motive force must be produced in order to overcome the resistive force

Question 43

the human musculoskeletal system is designed for increased

Answer 43

linear range of motion and velocity

Question 44

many musculoskeletal arrangements in the human body can be classified as

Answer 44

third class lever systems

Question 45

pulley system

Answer 45

consists of an object that acts as a wheel around which a flexible cord is pulled

Question 46

major functions of pulley systems

Answer 46

change the effective direction of the applied force, transmit forces, gain an advantage in force by changing the angle of pull for the muscle

Question 47

angle of pull

Answer 47

the angle at which the muscle force acts relative to a given axis or lever.

Question 48

wheel and axle system

Answer 48

consists of an object acting as a wheel that is secured to a smaller wheel, called the axle

Question 49

when either the wheel or axle rotates

Answer 49

the other part of the system rotates

Question 50

function of wheel and axel system

Answer 50

transmit a force, gain an advantage in force or linear range of motion and velocity

Question 51

wheel and axle system is actually a lever with

Answer 51

a tangential force applied to a moment arm that is equal to the radius of the wheel or axle

Question 52

motive force is applied where in wheel and axel system

Answer 52

outside of the wheel

Question 53

the force is eccentric in wheel and axel, what is produced

Answer 53

torque

Question 54

the large the wheel, the more

Answer 54

off-axis the force is applied

Question 55

a large wheel provides a

Answer 55

large moment arm for the applied force

Question 56

compared to the wheel, the axels radius is

Answer 56

small

Question 57

if force is applied to axel then

Answer 57

torque production is compromised

Question 58

motive force must be applied where to wheel and axle

Answer 58

wheel which provides advantage in force

Question 59

in wheel and axle, to gain an advantage in linear range of motion and velocity

Answer 59

apply the motive force to the axle

Question 60

example of wheel and axle in the musculoskeletal

Answer 60

skull and torso rotating with the spine, skull and torse wheel that rotate around axle spine

Question 61

what is static equilibrium

Answer 61

a situation in which the system is in linear and rotation equilibrium and possesses zero linear or rotational velocity

Question 62

what is dynamic equilibrium

Answer 62

system in motion, but is experiencing no change in velocity or direction

Question 63

linear stability

Answer 63

resistance of a body to having its linear equilibrium disrupted

Question 64

rotational stability

Answer 64

the resistance of a body to having its rotational or angular equilibrium disrupted

Question 65

ways to increase rotational stability

Answer 65

keep the center of gravity in the middle of the base of support, lower the center of gravity of object, move the center of gravity to one side of the base of the support, as long as its the same side of the base on which the external force will be applied