Math Question?

[Wallie]

A Backhoe weighing 8 tons is on top of a flatbed trailer and heading east on Interstate 70 near Hays, Kansas at 70 mph.


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 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.

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[Lurch]

I would have thought the trailer would have been ripped from the tractor first and long before that.

 

[Mr Bogus]

looks like 70 mph about filled the ticket.. .421 seconds to dead stop.. and about 6.5 g's

every picture of this happening I have ever seen usually flips the loader over on the trailer and out the back, never seen one actually penetrate the bridge/overpass... whew...

 

[BA BUSA]

Wow, that guy almost made it

 

[Wallie]

Wow, that guy almost made it

He would made it if he was doing 90 mph

 

[Dino]

Ummm....FAIL!

 

[Commuta_Busa]

he didn't make it because it's a Hyundai

 

[Mr Bogus]

uh boss? I got a flat...

 

[Wallie]

he didn't make it because it's a Hyundai

That tells you they make good equipment. I wish there car were that tough

 

[Commuta_Busa]

hmmm how much thrust would be needed for a hyundai azzure to penetrate a bridge?

That tells you they make good equipment. I wish there car were that tough

 

[wharthog3]

I work for a heavy equipment sales company and I just have to ask, HOW HOW HOW HOW did he not get the clearances of the route he was transporting that excavator on?!?! Or did he just not measure how tall the load was? We know every clearance of every overpass before we leave the shop.

That arm lays flat, just gotta curl the bucket under, see here's one at my work

HAHA, so to answer your question, 84mph would have clearly made it all the way through

 

[Wallie]

If you look at the pics the guys didn't slice the bridge. what you see on the first pics is all the debry from the hole that was made fron the arm. HTe trailes was going from right to left you can see the back of the flatbed. then if you look at thet secon pics from the bottom the excavator hit the bottom of the bridge. Anyway I would love to see a pic of the driver of the truck

 

[BlueHaya]

It actually pierced the bridge not sliced.

 

[BlueHaya]

If you look at the pics the guys didn't slice the bridge. what you see on the first pics is all the debry from the hole that was made fron the arm. HTe trailes was going from right to left you can see the back of the flatbed. then if you look at thet secon pics from the bottom the excavator hit the bottom of the bridge. Anyway I would love to see a pic of the driver of the truck

pinch pie poke ...you owe me a coke.

 

[dadofthree]

Sir, can I get your insurance information

 

[Wallie]

pinch pie poke ...you owe me a coke.

I have it delivered by the same driver if that ok w/ you

 

[BlueHaya]

I have it delivered by the same driver if that ok w/ you

 

[Projekt]

You think that guy will ever drive again?

 

[Revlis]

Interesting that there was enough energy to SLAP the shovel into the other side of the bridge.

Expensive... Interesting...


AND...



About 3 years old.

 

[Mr Bogus]

You think that guy will ever drive again?

if he can get the steering wheel out of his mouth...