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CHAPTER 9 Rotational Motion - Coggle Diagram
CHAPTER 9 Rotational Motion
9-1 Angular Quantities
θ=l/R
l=arc length
angular displacement
θ=θf-θi
angular velocity
ω=dθ/dt
angular accelelaration
α=dω/dt
Every point on a rotating body has an angular
velocity ω and a linear velocity v.
v=Rω
objects farther from the axis of rotation will move faster
9-6 Solving Problems in Rotational Dynamics
steps are show in notes!!
9-3 Constant Angular Acceleration
have same equations as linear motion just change the symbols
eg situation: centrifudge acceleration
9-7 Determining Moments of Inertia
I=∫R^2 dm
eg situation: cylinder,solid or hollow
I=Icm +Mh^2
eg situation: parallel axis
The parallel-axis theorem gives the moment of inertia about any axis parallel to an axis that goes through the center of mass of an object
the perpendicular-axis theorem is valid only for flat objects
Iz=Ix+Iy
9-2 Vector Nature of Angular Quantities
angular velocity vector points along the axis of rotation with the direction given by the right hand rule
9-5 Rotational Dynamics; Torque and Rotational Inertia
I=mR^2
The rotational inertia of an object depends not only on its mass distribution but also the location of the axis of rotation
9-10 Why Does a Rolling Sphere Slow Down?
force would cause : the frictional force act at the point of contact
gravity and the normal force both act through the center of mass and cannot create a torque
9-8 Rotational Kinetic Energy
K= Σ(1/2 mv^2)
9-4 Torque
To make an object start rotating, a force is needed; the position and direction of the force
matter as well
perpendicular from the point call lever arm.longer lever arm help in rotating objects
torque on a compound wheel
9-9 Rotational Plus Translational Motion; Rolling