b. air resistance experiences equal forces of gravity and air resistance     A full lake is dropping at its constant rate, meaning it is unchanging over time. After 4 weeks’ time, it already dropped 3 feet. Now, let’s solve for the Unit rate based on the given data. => 3 feet in 4 weeks => Unit rate is 3 feet per 4 weeks => in 4 weeks there are (7 * 4) = 28 days => 3 feet / 28 days   => the Unit rate is .107 feet / day