Engineering Quiz Time

Challenge yourself here:

A Backhoe weighing 8 tons is on top of a flatbed trailer and headingeast on Interstate 70 near Hays, Kansas. The extended shovel arm ismade of high tensile steel and the approaching overpass is made ofcommercial-grade concrete, reinforced with 1 1/2 inch steel rebarSpaced at 6 inch intervals in a crisscross pattern layered at 1 footvertical spacing.

Solve: When the shovel arm hits the overpass, how fast do you have tobe going to slice the bridge in half? (Assume no effect for headwindand no braking by the driver...)

I thought I had blogged this already... but this is a new slant...

[Thanks Catherine]