Q1. A boat moves through the water of a river at 9 m/s relative to the water, regardless of the boat's direction. If the water in the river is flowing at 1.9 m/s, how long does it take the boat to make a round trip consisting of a 225 m displacement downstream followed by a 215 m displacement upstream?

Q2. A storage tank 25m high is filled with gasoline.

(a) Find out the gauge pressure at the bottom of the tank.

(b) Compute the force that acts on a square access hatch at the bottom of tank that measures 0.25 m by 0.25 m.