Answer
The submarine's acceleration has a magnitude of $0.62m/s^2$ and points upward.
Work Step by Step
There are 3 forces in consideration here:
- The weight of the submarine: $mg=1450\times9.8=14210N$
- Buoyant force $B=16140N$
- Resistive force $R=1030N$
$\vec{B}$ is the only force upward, while the other 2 force point downward. Therefore, $$\sum F=B-mg-R=900N$$
Newton's 2nd Law of Motion: $$\sum F=m_{sub}a$$ $$a=\frac{900}{1450}=0.62m/s^2$$
$a\gt0$ means that its direction is the same as $\vec{B}$, which is upward.
