10,000N vehicle stalls 1/4 way across the bridge. Calculate the forces on boths ends of the bridge.?

Question

I think that it would be 7,500 N on the end closest to the vehicle and 2,500 N on the far end - does this seem right?

Answer 1

The key point to remember is that moments of this system around any one point should be zero. So assume that you choose the hinge point to be the closer end, we have a 10000*1/4 downward moment (its downward because the weight of the car acts downwards) and the reaction at the far end (say X) should be X*1.0. Therefore you have X = 2500. However the 10000N downward force also needs to be balanced completely. As 10000-2500 = 7500 remains to be balanced, the closer end should have 7500N upward reaction force.