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**A boxcar of length 8.00 m and height 2.40 m is at rest on frictionless rails.**

The empty boxcar has a mass of 3750 kg. Inside the boxcar, located at the left end, is a tank containing 2450 kg of water. The tank is 2.00 m long and 2.40 m tall. The tank starts to leak, and the water fills the floor of the boxcar uniformly. Assume that all the water stays in the box car.

**1)**What is the displacement of the boxcar 14 s after the water has settled in the bottom?

SO my original thinking was that the final velocity of the boxcar will be zero after all of the water has leaked out. What I've been trying to do is find the

**Center of Mass**of the boxcar initially and subtracting it from 4m, which I believe to be the final center of mass once the water has settled. Taking the lower left corner of the boxcar as the origin:

I went X

_{cmi}= (4m)(3750kg boxcar) + (1m)(2450kg tank), and dividing this by the total mass (3750kg + 2450kg) to get 2.9m. Then when I go 4m - 2.9m, I get 1.19m which I thought would be the displacement, but I was wrong.

Could anybody steer me in the right direction? I know I'm close, I'm just not quite sure what to do from here.