1. A square tank, 3 m on a side, is filled with water to a depth of 2 m. A vertical slot 6 mm wide from the top to the bottom allows the water to drain out. Determine the height h as a function of time and the time necessary for one half of the water to drain out.

2. A body falls from rest and is resisted by air drag. Determine the time necessary to reach a velocity of 50 m/s if the 100-kg body is resisted by a force equal to

(a) 0.01v and

(b) 0.004v².

Check if the equation M(dv/dt) = Mg - D, where D is the drag force, describes the motion.