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Hinges and moments

I have attached a photo of the question and my workings. I just don’t get why the force at the hinge has a resultant that is below the horizontal.

Thanks

image.jpg428.5KB

Reply 1

ghostwalker

Original post by maggiehodgson

I have attached a photo of the question and my workings. I just don’t get why the force at the hinge has a resultant that is below the horizontal.

Thanks

The reaction at the hinge must be upwards and away from the wall. Your direction for R is correct.

Edit: Not checked the actual calculation.

(edited 2 years ago)

Reply 2

mqb2766

As ghostwalker said, there must be a vertical upwards reaction on the rod from the wall and your working looks ok, without seeing the question. Just consider taking moments about B, the two masses act clockwise, the vertical wall reaction must act anticlockwise (up).