Center of Gravity Chapter 10

Center of Gravity (CG) The point located at the object’s avg. position of weight. Seems as though all the weight is concentrated around this point

Center of Gravity Uniform object: at the midpoint Baseball at the center Irregularly shaped object Bat is near the heavier end Discuss hammer

Motion Projectile parabolic path of its center of gravity Hammer toss

Motion Projectile wobble around its center of gravity because cg is off center Example: Sun and stars as the system orbits, the cg is displaced

Motion Smooth Path straight line motion of its center of gravity pg. 137 rotation around its center of gravity Hammer slide across floor

Locating CG Uniform Object Can be found by suspending an object by two or more points and looking at the lines of intersection Uniform Object CG is a balance point supporting that single point supports the entire object Can be located where no material exists - doughnut Hewitt

Toppling CG must be over the base in order to not tip over Examples Leaning Tower of Pisa Chair demo Monkeys - tail allows a shift in the cg and increase stability CG must be over your feet for you to be stable

Toppling Demos Pick up the money Stand up! Up against the wall! Monkeys/Dinosaurs

Stability Center of gravity seeks lowest point Stable – if displaced, cg goes up Unstable - if displaced, cg goes down Neutral – if displaced, cg the same