Question

A scientist uses a submarine to study ocean life. She begins at sea level, which is an elevation of 0 feet. She descends for 21 seconds at a speed of 3.3 feet per second. She then ascends for 12 seconds at a speed of 2.4 feet per second. After this 33-second period, how much time, in seconds, will it take for the scientist to travel back to sea level at 4.2 feet per second? If necessary, round your answer to the nearest tenth of a second

Answer 1

The scientist will take approximately 23.4 seconds to travel back to sea level.

Step-by-step explanation:

To find the time it takes for the scientist to travel back to sea level, we need to calculate the total distance she travels during the descent and ascent.

During the descent, she travels 3.3 feet per second for 21 seconds, so the total distance is 3.3 * 21 = 69.3 feet.

During the ascent, she travels 2.4 feet per second for 12 seconds, so the total distance is 2.4 * 12 = 28.8 feet.

Therefore, the total distance she travels is 69.3 + 28.8 = 98.1 feet.

Since she travels back to sea level at a speed of 4.2 feet per second, we can calculate the time it takes using the formula Distance = Speed * Time.

98.1 = 4.2 * Time.

Time = 98.1 / 4.2 = 23.36 seconds.

Rounded to the nearest tenth of a second, it will take approximately 23.4 seconds for the scientist to travel back to sea level.