Liz, Jay, and Tara discover that sinister chemicals are leaking at a steady rate from a hole in the bottom of a railway car. To collect evidence of a potential environmental mishap, they videotape the car as it rolls without friction at an initial speed v0. Tara claims that careful analysis of the videotape will show that the car's speed is increasing, because it is losing mass as it drains. The increase in speed will help to prove that the leak is occurring. Liz says no, that with a loss of mass, the car's speed will be decreasing. Jay says the speed will remain the same.

(a) Who is right?

(b)What forces are exerted on the system of the car plus chemical cargo?