Question

A submarine begins at -215 feet below sea level. If the sub travels at 20 feet per minute, how many minutes will it take for the sub to rise to the surface and then descend to -104 feet?

Answer 1

To determine the time for a submarine's movement, calculate the time to rise from -215 feet to the surface and the time to descend to -104 feet at a speed of 20 feet per minute. The total time is approximately 15.95 minutes.

Step-by-step explanation:

The question involves calculating the time it will take for a submarine to rise from -215 feet to the surface (0 feet) and then descend to -104 feet. The submarine rises and descends at a constant speed of 20 feet per minute. To begin, we calculate the time to rise to the surface as follows:

• Rise to surface: -215 feet to 0 feet = 215 feet.
• Time to rise = distance/speed = 215 feet / 20 feet per minute = 10.75 minutes.

The next step is to calculate the time to descend to -104 feet from the surface:

• Descend to -104 feet: 0 feet to -104 feet = 104 feet.
• Time to descend = distance/speed = 104 feet / 20 feet per minute = 5.2 minutes.

Adding both times gives the total time for the entire journey:

1. Total time = Time to rise + Time to descend = 10.75 minutes + 5.2 minutes = 15.95 minutes.

Therefore, it will take approximately 15.95 minutes for the submarine to rise to the surface and then descend to -104 feet.