Center of Mass and Work Problem

[JoeyM88]

Homework Statement

Explorers in the jungle find an ancient monument in the shape of a large isosceles triangle . The monument is made from tens of thousands of small stone blocks of density 3 174 kg/m3. The monument is 17.6 m high and 69.4 m wide at its base and is everywhere 3.30 m thick from front to back. Before the monument was built many years ago, all the stone blocks lay on the ground. How much work did laborers do on the blocks to put them in position while building the entire monument?

Homework Equations

Work = (Mass*Gravity*Center of Mass)

The Attempt at a Solution

Volume=(17.6*69.4*3.30)=4030.752
Mass = (3174*4030.752)=12793606.85kg
Center of Mass=?
Work=(12793606.85kg*9.8*Center of Mass)

 

[SEngstrom]

your volume is what a rectangular shape would have (twice too large).
the center of mass for a triangle is the centroid.