Answer:
-2.5

Step-by-step explanation:
We can use the kinematics equation below to find the boat's acceleration.

Lets solve for
.
Subtract
from both sides of the equation.

Divide each term in
by
.

Simplify the left side.
Cancel the common factor of 2.

Cancel the common factor of x.

Simplify the right side.
Move the negative in front of the fraction.

Now we have an equation for
.
We are given

Substituting our numbers into the equation gives us



