- #1
JiggaMan
- 4
- 0
Homework Statement
The 3.0 kg rod has a length of 80 cm. The 4.0 kg rectangle attached to the rod has negligible dimensions. The entire object rotates counterclockwise about the bottom of the rod. Determine the angular speed of the apparatus at the instant the rod is horizontal.
https://gyazo.com/9d0bb4ce2fed98b192f173a918549f60
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Homework Equations
mgh = potential energy
( w^2 * i ) * .5 = rotational energy
i = moment of inertia
moment of intertia for rod rotated on end = (m * L^2) * .333
L = length
m = mass
w = angular speed
THE ANSWER SHOULD BE 5.19 rad/s
The Attempt at a Solution
*For the height, I found the center of gravity which is .63 meters, i think the length stays .8 though
mgh = (w^2 * i ) * .5
mgh = (w^2) * (m * L^2) * .333 * .5
7 * 10 * .63 = ( w^2 ) * (7 * .8 * .8 ) * .333 * .5
44.1 = (w^2) * .746
59.115 = (w^2)
7.68 = w
7.68 rad/s ?[/B]