# Rotational dynamics rod- !

superaznnerd
rotational dynamics rod--plz help!

## Homework Statement

A thin rod of length l and mass m is fixed at a far ends by a free pivot and held from rotating with a string attached at 3/4l and fixed toa ceiling. The moment of inertia of a thin rod about a far end is ml2/3

a) what is the pivot point exerting on the rod

The rope is cut at t =0 seconds. at t =0 seconds find:
b) the angular acceleration of the rod.
c) the transverse acceleration of the rod's center of mass.
d) the transverse aceleration of point A (the far end of the rod)
e) the force exerted by the pivot point

picture is attached.

#### Attachments

• rotational dynamics 6.jpg
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Homework Helper

You have to at least try the problem and explain your thoughts before asking for help.

superaznnerd

First, total downward torque = upward torque.
.5mgl + Torque of pivot point = .75mgl
torque of pivot point = .25mgl.
This doesnt make sense because the pivot point cant exert a torque.
Thats all I got to...and I couldnt figure out anthing else lol
I have all the answers, I just need to understand hwo to do it.