# Homework Help: Trying to Find Center of Gravity on Semi Truck (a real one)

1. Oct 20, 2008

Trying to Find Center of Gravity on Semi Truck (a real one)!!

1. The problem statement, all variables and given/known data

For one of my classes I have to prove, using very basic physics, that a scene from a movie is very unrealistic. So my group chose the "truck flip scene" from Batman Dark Knight.

I am desperately searching to fond a site that can provide me with the approximate location of the center of gravity of a tractor-trailer truck. I don't care what kind of truck or whether it is filled to capacity or if it's empty...I just need something with a number and possibly a picture.

I have tried googling so many different key phrases that I want to scream. I have tried "center of mass of semi trailer" "center of mass of tractor trailer" "center of gravity of semi trailer" "center of gravity of tractor trailer"

and countless variations.

I know that it is obnoxious to outright ask someone to google it for me, but I could really use some advice on how to refine my search better.

Any pointers would be greatly appreciated.

Casey

2. Oct 20, 2008

Re: Trying to Find Center of Gravity on Semi Truck (a real one)!!

My eyes feel like they are going to bleed. Any ideas?

3. Jan 5, 2009

### lobstaz1

Re: Trying to Find Center of Gravity on Semi Truck (a real one)!!

Wow.... i am actually doing the exact same thing for my physics summative (grade 12) and need the approximate center of mass as well....

For the other stats on the semi i have:
avg length: 75 feet = 22.86 meters
avg unloaded weight: 14 000 kilograms = 30 864.7167 pounds

Tensile strength of steel (for batman's cables): 1860MPa
Tensile strength of carbon nanotube rope (incase Batman has miraculously advanced this new technology): 62000MPa

What was your estimate on the truck's speed? I was thinking 60 km/h... but im not too sure on that.

4. Jan 5, 2009

### TVP45

Re: Trying to Find Center of Gravity on Semi Truck (a real one)!!

If you only need an approximate value, this state weight inspection link will enable you to calculate that.
http://www.dot.state.pa.us/Internet/Bureaus/pdBOMO.nsf/infoRMCPHeightAndWeight?OpenForm [Broken]

Last edited by a moderator: May 3, 2017