Final answer:
The submarine's elevation after ascending 9 feet is 221 feet below sea level. Calculation is performed by adding the ascent to the starting elevation: -230 + 9 = -221 feet.
Step-by-step explanation:
When a small submarine ascends 9 feet from an elevation of 230 feet below sea level, the operation you need to perform to find its new elevation is essentially an addition. Since descending below sea level is typically represented by negative numbers, the submarine's starting elevation is -230 feet. To represent ascending, you add the number of feet it rises. In this case, you're adding 9 feet, which is a positive number.
To calculate the submarine's new elevation, you simply add the ascent distance to the original elevation:
- Starting elevation: -230 feet (below sea level)
- Ascent: +9 feet
- New elevation: -230 + 9 = -221 feet (below sea level)
The submarine's elevation after it ascends 9 feet is 221 feet below sea level.