Final answer:
The average speed of the boat heading north is 4 feet per second.
Step-by-step explanation:
To find the average speed of the boat heading north, we need to first find the time it took for the boat to travel each distance. We can find the time by dividing the distance traveled by the speed. Let's denote the speed heading north as S and the speed heading east as S - 4.
For the distance traveled heading east, we have:
14 feet = (S - 4) feet/second * time
For the distance traveled heading north, we have:
54 feet = S feet/second * time
Since the total distance is 68 feet and the total time is 16 seconds, we can write:
14 feet + 54 feet = (S - 4) feet/second * time + S feet/second * time
68 feet = S*time + S*time - 4*time
68 feet = 2S*time - 4*time
68 feet = (2S - 4)*time
68/((2S - 4)) = time
Now, we can substitute the value of time into the equation for the distance traveled heading north to find the speed:
54 feet = S feet/second * (68/((2S - 4)))
Solving for S, we get:
S = 4 feet/second