Friday 15 February 2008

Engineering physics calculation

Problem: A backhoe weighing 18 tons is on top of a flatbed trailer. The boom and dipper stick is made of 80,000 psi high strength steel and the approaching overpass is made of 4,000 psi concrete, reinforced with 2 layers of 1 inch steel rebar spaced 6 inches each way in both the road deck and bottom of the box-beam bridge section.

Solve: When the boom and dipper hits the overpass, how fast does the trailer with the backhoe have to be going to slice the bridge in half? (Assume no headwind and no braking by the driver who is oblivious of the situation . . . )

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 .

Answer:

2 comments:

Anonymous said...

Aw come on. Newton's mechanics is just a theory.

psychics said...

I want to do a course in mechanical engineering, but how much is it about physics and maths? I was interested in doing motorsport engineering, but what do you actually do at university? Do you sit at a desk and do complicated calculations and look at the theory, or do you do a lot of practicle work? Also is there any design work in it?