Question

A boxcar of length 9.3 $m$ and height 2.4 $m$ is at rest on frictionless rails. Inside the boxcar (whose mass when empty is 3900 $kg$) a tank containing 1400 $kg$ of water is located at the left end. The tank is 1.1 $m$ long and 2.4 $m$ tall. At some point the walls of the tank start to leak, and the water fills the floor of the boxcar uniformly. Assume that all the water stays in the boxcar. What is the displacement of the boxcar 7 $s$ after the water has settled in the bottom. (Take positive displacement as being to the right.)

Answer 1