Engineering Math Question

Conditions:

A trackhoe weighing 22 tons is on top of a lowboy 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, re inforced with 1½ 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 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.

Yes, you can neglect friction.







I couldn't solve it either......but who cares;

The driver was on his cell phone.. ;p