1. TORQUE DEFINED
a Force applied a system restricted to moving in a circular path
causes a system/body to rotate
the Point of Application is eccentric
T = F x FA

2. MUSCLE TORQUES Magnitude - product of F x FA
Direction - angle of pull on bone
Line of Action - vector direction
Point of Application - attachment to bone

3. FA: FORCE ARM
shortest distance from axis of rotation to the line of action of the applied Force
 (perpendicular) to line of action

4. TEETER-TOTTER
Axis of Rotation
2 Forces
2 Force Arms

5. FIG E.8 Page 116 of textbook

6. FIG 9-30
“Basic Biomechanics”
3rd Edition
Susan J. Hall

7. CALCULATING TORQUE Force measured in Newtons [4.45N = 1Lb.]
Force Arm measured in meters
Torque measured in Newton meters [Nm]

8. FIG E.11 page 118
sum up all Torques on each side of axis
side of axis with the larger  of T determines direction of movement

9. Angular Motion Vectors
there are both kinetic and kinematic vectors
A vector is represented by a straight line arrow symbol
the length of the arrow is the magnitude
the orientation of the arrow is the direction
to get a straight line vector for angular motion, the right hand thumb rule is used

10. RIGHT-HAND THUMB RULE
method of determining vector direction for angular motion
curve fingers of right hand in the direction of the Torque
right thumb points in vector direction of the motion,  to the actual direction of the spin

11. Right-Hand Thumb points in vector direction
FIG 15.9 on page 506
FIG on page 507

12. CENTER of BUOYANCY
the location of the C of G of the volume of water displaced by a immersed body
body’s CB must be aligned with body’s CG for floating to occur