A scientist uses a submarine to study ocean life. She begins at sea level, which is at an elevation of 0. She travels straight down for 90 seconds at a speed of 3.5 feet per second. She then travels directly up for 30 seconds at a speed of 2.2 feet per second. After this 120 second period, how much time, in seconds, will it take for the scientist to travel back to sea level at the submarine's maximum speed of 4.8 per second. Round your answer to the nearest tenth of a second.

Respuesta :

Answer:

51.9 seconds

Step-by-step explanation:

First I multiplied 90 seconds by 3.5 fps (feet per second) to figure out how deep she went. I got 315 feet.

Second I multiplied 30 seconds by 2.2 fps to figure out how far she went back up. I got 66 feet.

I then subtracted 66 from 315 to get 249 feet.

After that I divided 249 feet by 4.8 fps to figure out how long it took her to get back to sea level and got 51.875 seconds, which rounded to the nearest tenth, is 51.9 seconds.

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