Throw a brick into the Mariana Trench, how long will it take to reach the bottom of the sea?

2020-12-29 | Science on the planet Original |

The Mariana Trench is the deepest known ocean on the earth, and it is also known as one of the harshest areas on the earth. Its deepest point can reach 6 to 11 kilometers. If the world’s highest mountain, Mount EverestPutting it into the Mariana Trench, there is no way to expose the top. Many climbers can successfully climb the Mount Everest, but it is difficult for us to conquer the Mariana Trench. Since the Mariana Trench is so deep, if we throw in a pieceBrick, how long will it reach the bottom of the sea?

The Mariana Trench is not only high in water pressure, but also low in temperature and oxygen content. It is part of a series of trenches in the western Pacific Ocean floor. It is formed by the collision between the Asia-Europe plate and the Pacific plate.As a continental plate, the European plate rises to form an island arc after collision, while the Pacific plate, as an oceanic plate, sinks to form a trench after the collision. This trench is the Mariana Trench. It has a total length of 2550 kilometers and an arc as a whole.According to statistics, it has been formed about 60 million years.

Human beings are also constantly exploring the mysteries of the Mariana Trench. China has also made major breakthroughs in its exploration. Since 2012, China has launched the manned submersible Jiaolong into the Mariana Trench for investigation and exploration.The mystery of the deep sea, the first test dive successfully dived 6671 meters underwater.

Afterwards, the Jiaolong conducted a total of six test dives in the Mariana Trench. Among them, the deepest dive depth reached 7062.68 meters. Until November 10, 2020, the Chinese manned submersible "Fight" successfully launchedThe Mariana Trench sits on the bottom and has a depth of 10,909 meters.

This time let’s take a look. Throw a brick into the Mariana Trench. How long will it take for it to reach the bottom of the sea? First, can the brick sink successfully? If the Mariana Trench increases in depth, the seawaterThe density is always lower than the density of the bricks, so the bricks can successfully sink, but it is a matter of time. But if the density of the seawater is higher than the density of the bricks at a certain point, the bricks have to be suspended in the trenchbingo.

According to survey statistics, the atmospheric pressure at the bottom of the Mariana Trench is equivalent to 1,100 atmospheres, and the water density at the deepest 11 kilometers is about 1,050 kg/m3. The sea is affected by various mineral salts and impurities.The density will be relatively large, but it will not exceed 1080 kg/m3. The density of an ordinary brick is about 1800 kg/m3, so the density of the brick is higher than the density of the seawater deep in the trench, and the brick can be successfulSink to the bottom of the trench.

This brick thrown into the Mariana Trench will be affected by its own gravity, the buoyancy of the seawater and the resistance of the seawater during its descent. The brick will continue to accelerate as the speed increases during the descending process., The resistance it receives will become greater and greater. At this time there will be a terminal speed, that is, when the resultant force of the brick downward is equal to the resistance it receives, the brick has reached the highest descending speed at this time..

If the brick with its smallest area is facing down, it continues to sink into the trench. In this case, the projected area of ​​the brick is about 6095 square millimeters and the drag coefficient is 0.47. We can calculate the terminal speed of the brick, It is about 2.73 m/s, so it takes about 67 minutes for the bricks to sink to the bottom of the Mariana Trench at the fastest.

We explored how long it would take for a brick to be thrown into the Mariana Trench to reach the bottom of the sea. It was just a survey and study. We learned to live in harmony with nature and cannot really throw bricks and other pollutants into the Mariana Trench. According to oneThe results of this study show that in the 2673-10908m bottom seawater of the Mariana Trench, the content of microplastics is higher, and the content of most deep-sea sediments is higher, and there is obvious marine pollution.

The pollution of the ocean will endanger the entire marine ecosystem. The destiny of nature is closely linked to the destiny of mankind. If the ocean is seriously polluted and nature is seriously harmed, we humans will also be harmed. So from now onLet’s start with ourselves and protect our nature.

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