SECTION $9\mathrm{.}8$ Free Fall and the Coriolis Force

$9\mathrm{.}25*$ A high$-$speed train is traveling at a constant $150\frac{m}{s}($about $300$ mph $)$ on a straight, horizontal track across the South Pole. Find the angle between a plumb line suspended from the ceiling inside the train and another inside a hut on the ground. In what direction is the plumb line on the train deflected?