Calculate the Initial Calue of the Force at the Bearing

[Northbysouth]

Homework Statement

The uniform slender bar is pivoted at and swings freely in the vertical plane. If the bar is released from rest in the horizontal position, calculate the initial value of the force exerted by the bearing on the bar an instant after release.

I have attached an image of the question

Homework Equations

The Attempt at a Solution

I'm honestly not sure how to start this question. I'm pretty sure that this is a straightforward question

I think I may need to use the equation:

ƩM_O = I_Gα + ma_Gd

Any advice would be appreciated. Thank you

 

[Northbysouth]

Ahh, wait I've figure it out now.

I used the fact that:

ƩM_O: I_Gα = -mg(L/2)

Solving for α = -mg(0.5L)/I_G

where L is the length of the bar

Then I applied a normal and tangential coordinate system, with t pointing downwards and n pointing towards O.

ƩF_t: mrα = O_y - mg

Plugging in the formula that I solved for α above I get

Oy = mr[-mg(0.5L)/I_g] + mg

My final answer was 88.29 N