There is a sign hanging off of a building. The sign itself is hung at the far end of a rod. The rod is held up by both a pivot on the building's wall, and a vertical cable attached 1 m away from the building to the rod. The cable and the rod make a right angle.
The rod has mass 30 kg, length 4 meters, the sign has mass 30 kg.
This may be confusing, so here's my feeble attempt at a picture:
(the pivot is located at this intersection: ]__ )
]
] | cable
]__1m_|___3m___
] rod = 30 kg |
] |
] [50kg] = sign
Now, how would I find the force the pivot exerts on the rod? I know there should be no horizontal force, but I don't know how to find the vertical force.
Oh, no!! I didn't realize my picture would be reformatted!! I'll post a link to a better drawn image in a few minutes.
img31*picoodle*com/img/img31/9/8/15/f_phypicm_bfa429c.jpg
(replace *'s with .'s)
I hope that helps.