A submarine dives 270 feet below the ocean's surface. It then rises 90 feet, rises another 40 feet, and finally dives 55 feet. What action is required by the submarine to get back to the surface?

The action required by the submarine to get back to the surface is to rise 195 feet

Step-by-step explanation:

we know that

The ocean's surface or sea level is at an elevation of 0 feet.

we have

1) A submarine dives 270 feet below the ocean's surface

In this moment the position of the submarine is

-270 ft - --> is negative because is below the sea level

2) It then rises 90 feet

In this moment the position of the submarine is

-270+90=-180 feet

3) rises another 40 feet,

In this moment the position of the submarine is

-180+40=-140 feet

4) Finally dives 55 feet

In this moment the position of the submarine is

-140-55=-195 feet

therefore

The action required by the submarine to get back to the surface is to rise 195 feet