Overpass Passover
Bridging The Gap or Gap In The Bridge?
Engineering Quiz
A trackhoe weighing 8 tons is on top of a flatbed trailer and heading east on
Interstate 70
near Hays, Kansas. The extended shovel arm is made of hardened refined steel and
the approaching overpass is made of commercial-grade concrete, reinforced with 1
1/2 inch
steel rebar spaced at 6 inch intervals in a crisscross pattern layered at 1 foot
vertical spacing.
Solve: When the shovel arm hits the overpass, how
fast do you have to be going to slice
the bridge in half? (Assume no effect for headwind and no breaking by the
driver...)
Extra Credit: Solve for the time and distance
required for the entire rig to come to a
complete stop after hitting the overpass at the speed calculated above.
Answer - Who cares, the trucking company just
bought themselves a bridge…
