Question

A diver is exploring the waters of the Great Barrier Reef.

Part A. She is currently -5 feet from the surface of the water and plans to explore a shipwreck that is at -75 feet from the surface. If she moves at a rate of -8 feet per minute, how many minutes does it take the diver to reach the shipwreck?

Part B. When she is done exploring the reef, she ascends at a rate of 5 feet per minute. Once she reaches a height of -30 feet, she must rest for 15 minutes to allow her body to adapt to the changing water pressure. She then continues to the surface at the same rate. How long does it take the diver to reach the surface? ​

Answer 1

• 8 3/4 minutes
• 30 minutes

Explanation:

Part A

The change in depth from -5 ft to -75 ft is ...

-75 -(-5) = -70 ft

At the rate of -8 ft/min, it will take this long to reach the desired depth:

time = distance/speed

= (-70 ft)/(-8 ft/min) = 70/8 min = 8 3/4 min

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Part B

Ascending from -75 ft to 0 ft at the rate of 5 ft/min will take ...

time = distance/speed

= (0 -(-75 ft))/(5 ft/min) = 75/5 min = 15 min

Adding a 15 minute rest will bring the total travel time to ...

(15 min) + (15 min) = 30 min