Once a falling has reached a constant velocity, the object

 A. stops accelerating 
  B. stops speeding up 
  C. experiences equal forces of gravity and air resistance 
  D. all of the above

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