Rotational Equilibrium

1
Rotational Equilibrium

• Torque
• Equilibrium
• Center of Gravity

2
Torque Magnitude

• Torque is product of distance to force and amount
  of force _______________ to distance
• Alternate interpretation in terms of ____ ___ (c)

Fig. 8.3, p. 230
3
Torque Direction

• Point fingers of ______ hand in direction of r
• Curl fingers _________ direction of F
• Thumb points in direction of ________
• ? is ? _____ of r and F
• Fingers curl in direction of __________ torque
  produces on object at rest

Fig. 8.4, p. 231
4
Extending Newtons Laws

1. Rotation of an object doesnt change unless acted
   on by an ________ ______
2. Angular acceleration, ?, is ___________ to
   torque, ? . (As long as mass distribution doesnt
   change more later.)
3. Torques come in _______

5
Equilibrium

• Net external force must be zero
• Net external torque must be zero

Fig. 8.6, p. 232
6
Center of Gravity

• Point where application of a single force on
  point object of same mass results in same torque

• Same form for y and z

Fig. 8.7, p. 234