Rotational Motion & Gravity

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Rotational Motion & Gravity
2014-05-25 11:54:02
Chapter Seven
H Physics
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  1. rotational motion
    motion of a body that spins about an axis
  2. tangential speed
    an instantaneous linear speed of an object directed along the tangent to the object's circular paths
  3. tangential acceleration
    • the instantaneous linear acceleration of an object directed along the tangent to the object's circular path
    • due to changing speed
  4. centripetal acceleration
    • acceleration directed toward the center of a circular path; radially inward
    • object in circular path whose acceleration changes only because of direction has this
  5. gravitational force
    • the mutual force of attraction between particles of matter
    • always exists between two masses, regardless of medium between them or size
  6. period
    • time for an object to complete one uniform motion (back and forth, around a circular path)
    • t=circumference/v
  7. frequency
    • the number of times something happens per given unit of time
    • f=1/t
  8. force that maintains circular motion
    • inertia would cause object to follow a straight line
    • string or medium counteracts this by exerting a force on the object, directed along its length towards the center of the circle
  9. force that pushes things outward in centripetal acceleration, overcoming this
    • centrifugal force
    • friction between the thing stopping the object from going outside its path maintains the circular motion
  10. strength of gravitational force
    • decreases as the masses move further apart
    • proportional to the mass of an object
  11. Newton's shell theorem
    • a uniform spherical shell of matter attracts a particle that is outside the shell as if the shell's mass were concentrated at its centerĀ 
    • attractive force is directed along the line of centers for the two objects