Question

A hiker who weighs 889 N, is strolling through the woods and crosses a small horizontal bridge. The bridge is uniform, weighs 3690 N, and rests on two concrete supports at each end. He stops one-fifth of the way along the bridge. What is the magnitude of the force that a concrete support exerts on the bridge at the near end?

Answer 1

Sum moments about either end. I will do it from the far end.

weightbridge*1/2 L+ 4/5L*889-force*L=0

solve for force.

Answer 2

what is L?