A 214 kg boat is sinking in the ocean. The force of gravity that draws the boat down is partially offset by the buoyant force of the water, so the net unbalanced force on the boat is –1,310 N. What is the acceleration of the boat?

Question

A 214 kg boat is sinking in the ocean. The force of gravity that draws the boat down is partially offset by the buoyant force of the water, so the net unbalanced force on the boat is –1,310 N. What is the acceleration of the boat? 
 m/s2

Anonymous · Accepted Answer

well, if the force is -1310 and the mass is 214 then
-1310 / 214 = a

HOWEVER this question is really dumb.
The effective mass includes the water in the boat so it is far more than the boat mass. Moreover when you accelerate in water you accelerate some of the water around you. In Naval Architecture we call that "added mass". For a sphere it is about the same as the volume of the sphere times the density of the water.