Wk 6 - Torque, levers, COG

Question 1

Clock wise torque =

Answer 1

positive motion

Question 2

Counter clockwise torque =

Answer 2

negative motion

Question 3

Torque is the _____ _____ of a force about an axis of rotation

Answer 3

turning effect

Question 4

Torque = ___ x ___

Answer 4

T = F x perpendicular distance (d or s)

Question 5

a ______ is the perpendicular distance from an axis to the line of action of a force

Answer 5

moment arm

Question 6

A moment arm is the…

Answer 6

is the perpendicular distance from an axis to the line of action of a force

Question 7

Is torque a force?

Answer 7

No

Question 8

Torque is the _____ of a force causing ____ about an axis

Answer 8

effectiveness, rotation

Question 9

Power =

Answer 9

F x d / t

Question 10

Fulcrum (F) is the..

Answer 10

point of suspension or axes of rotation (point where it pivots)

Question 11

Effort (E) on lever is …

Answer 11

the point where force is applied

Question 12

Load (L) on lever is ….

Answer 12

where load or resistance is applied

Question 13

First class lever system

Answer 13

F ulcrum in the middle of E and L. (see-saw like. e.g. head and neck)

Question 14

Second class lever system

Answer 14

Load in between fulcrum and effort (wheel barrow. e.g. calf raise)

Question 15

Third class lever system

Answer 15

Effort between load and fulcrum (elbow joint, most prominent in the body)

Question 16

Torsional lever (fourth class)

Answer 16

Load in directly above fulcrum, force causes rotation

Question 17

Mechanical advantages is defined as…

Answer 17

ratio of the effort arm to the resistance arm (MA = effort arm / resistance arm)

Question 18

If the fulcrum to load distance is > fulcrum to effort distance =

Answer 18

provides a distance / speed advantage (load moves further than effort in same time)

Question 19

If the fulcrum to load distance is < than fulcrum to effort distance =

Answer 19

provides a FORCE advantage (load is greater than the effort applied)

Question 20

If mechanical advantage > 1 =

Answer 20

Force advantage

Question 21

If mechanical advantage < 1 =

Answer 21

Speed / distance advantage

Question 22

COG is the point where…?

Answer 22

a body’s weight is equally balanced in all directions

Question 23

Stability -

Answer 23

resistance to disruption of equilibrium

Question 24

Balance -

Answer 24

ability to control equilibrium

Question 25

If displacement is due to work done by force and returns to original position = this is..?

Answer 25

Stable equilibrium

Question 26

If displacement is increased =

Answer 26

Unstable equilibrium (person doing head stand)

Question 27

If displaced and moves to new position =

Answer 27

neutral equilibrium (ball on flat surface with force applied)

Question 28

increased weight, _____ stability

Answer 28

increased weight, increases stability

Question 29

_______ friction, increases stability

Answer 29

increased

Question 30

increasing size of base of support = _________ stability

Answer 30

Increased stability