Saturday, December 06, 2008


All you engineers out there whip out your programmable HP calculators. 

I have a quiz for you.

TOH sent me this email the other day with the following problem:


A backhoe 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-enforced with 1 1/2 inch steel rebar spaced at 6 inch intervals in a criss-cross 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 pictures are great!

The driver was on his cell phone.................. 
Every now and then TOH sends me something very entertaining.


Hrbek said...

u had me at "backhoe"

Erwin Blonk said...

I have used programmable HP's in the artillery to get 100 pound grenades at the requested destination, at the requested time of detanation. But I'm not sure if it would have caused as much damage.

Bill Starr said...

Thanks for posting this.

Posted a link on Twitter.

Bill Starr
Thu, 5 Feb 2009, 4:34 pm EST

Bill Starr said...

Hello. I'm curious if you meant to block me on twitter and if it had anything to do with my posting a link to this post on your blog.

Bill Starr
Sun, 15 Feb 2009, 6:32 pm EST

Gadzooks64 said...


No, it had nothing to do with your link to my blog.

I block people that I don't personally know or have nothing in common with.

No offense is intended.