Question

A train engine that weighs $5000N$ stops at the exact centre of a bridge of weighs $75,000N$ and has two equally spaced pillars to support the bridge. Calculate the force exerted on the ground by a single pillar:

• A. $75,000N$
• B. $40,000N$
• C. $37,500N$
• D. $2500N$
• E. $0N$

Answer 1

The correct option is B $40,000N$

The weight of the bridge acts on its center of mass and as the pillars are equidistant from the centre, thus the normal reactions are same by both the pillars.

From figure, $2R=75000+5000$ $R=40000$ N