Engineering Quiz Time
A Backhoe 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 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
braking 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.
