![]() |
BIG ENCYCLOPEDIA FOR CHILDREN AND ADULTS
What is a sound barrier? Detailed answer Directory / Big encyclopedia. Questions for quiz and self-education Did you know? What is a sound barrier? The term "sound barrier" does not correctly describe the conditions that occur when an aircraft is moving at a certain speed. It can be assumed that when the aircraft reaches the speed of sound, something like a "barrier" appears - but nothing of the kind happens! To understand all this, consider an airplane flying at a slow, normal speed. As the aircraft moves forward, a compression wave forms in front of the aircraft. It is formed by an aircraft moving forward, which compresses air particles. This wave travels ahead of the aircraft at the speed of sound. And its speed is higher than the speed of the aircraft, which, as we have already said, flies at a low speed. Moving ahead of the aircraft, this wave causes air currents to flow around the plane of the aircraft. Now imagine that an airplane is flying at the speed of sound. There is no compression wave in front of the aircraft, since both the aircraft and the waves have the same speed. Therefore, the wave is formed in front of the wings. As a result, a shock wave appears, which creates large loads on the wings of the aircraft. Before aircraft reached and exceeded the sound barrier, it was believed that such shock waves and g-forces would create something like a barrier for the aircraft - a "sonic barrier". However, there was no sound barrier, as aeronautical engineers developed a special aircraft design for this. By the way, a strong "bang" that we hear when an aircraft passes the "sonic barrier" is the shock wave that we have already talked about - at an equal speed of the aircraft and the compression wave. Author: Likum A.
What causes ocean currents? There are huge masses of water in the sea that are constantly moving. Their circulation is very complex, as there are many other causes that make the water move. One of them is that dense water goes down, while lighter water goes up. The densest water in the ocean is cold and salty. This is what it becomes when sea water freezes in the Arctic Ocean and near Antarctica. There is very little salt in the ice resulting from this freezing. The cold salt water left after the formation of ice sinks into the depths of the sea. The saltiest water in the ocean is in the tropics. This water is very warm and therefore not as dense as the cold and less salty water below. It remains on the surface of the ocean. Salt water is moved by the winds. Sometimes the winds and the contours of the shore connect the moving masses of water together. The water is forced to flow faster, forming a current. The currents are like rivers in the sea. The most famous current is the Gulf Stream, which was discovered by Benjamin Franklin. The Gulf Stream begins in the Atlantic Ocean near the equator. Constant winds near the equator almost always blow from the east. They push warm salt water past the Caribbean islands into the vast bay formed by the Florida peninsula and the east coast of the United States. Water accumulates here and then flows north to Cape Hatteras. Here the Gulf Stream becomes narrow and flows quickly. Its speed is several kilometers per hour. The current here is less than 16 kilometers wide and about 550 meters deep. Like a river on earth, the Gulf Stream does not flow strictly straight, but wags along the ocean surface. But, unlike a river, the Gulf Stream is not always in the same place, as it does not have a definite course. Many surface currents, such as the Gulf Stream, have several other currents underneath them. They are called countercurrents. They move in the opposite direction, but along the same path as the main surface current. The rotation of the Earth around its axis also affects the formation of currents.
▪ In what city do almost all the inhabitants live in the same house? ▪ Which foreign leader was called Yuri as a child?
Artificial leather for touch emulation
15.04.2024 Petgugu Global cat litter
15.04.2024 The attractiveness of caring men
14.04.2024
▪ 24 GHz radar for motion and distance control
▪ section of the website Experiments in Physics. Selection of articles ▪ article Through the stump-deck (to bring down). Popular expression ▪ article Accountant for accounting of cash transactions. Job description ▪ article Multivibrator - flasher. Encyclopedia of radio electronics and electrical engineering ▪ article Miracle bottle. Focus secret
Home page | Library | Articles | Website map | Site Reviews www.diagram.com.ua |