Science & Mathematics Questions & Answers

Science & Mathematics Questions & Answers

How do sensor doors work?

Sensor doors use motion sensors or presence sensors. The first are used to activate the door when it detects a moving object, such as a pedestrian or shopping cart. Motion sensors can distinguish between objects moving toward the door or away from it. They use microwave technology, and utilize the Doppler Effect principle. The sensors emit a high frequency microwave …

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How do Satellites Stay Up?

Ten, nine, eight, seven… zero – lift off. These words sound like music to an astronomer’s ears. As the countdown progresses, the rocket’s engines fire and give it the required push to tear through the atmosphere and escape the earth’s gravitation. These rockets take astronauts and artificial or man-made satellites into space. The satellites are used for communication, weather monitoring …

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How do geologists help us?

All the sciences, mathematics, physics, chemistry, and biology, are playing an increasingly important role in our way of life, as the years pass and we become more dependent upon the products of science and technology. Geology, too, has a vital part to play in living today, apart from its value in furthering our understanding of the way in which our …

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How do clouds move in the sky?

Clouds are formed when water evaporates from rivers, ponds, oceans, and lakes. The tiny droplets of water cling to particles like (dust, salt, or smoke). The air containing this evaporated water vapour rises and expands at higher altitudes where the air pressure is lower and clouds move with the wind. High cirrus clouds are moved by a jet stream and …

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How do astronauts ‘walk’ in space?

If an astronaut leaves his spacecraft during a journey, he cannot walk about in the ordinary way. There is nothing but empty space. There is not even any gravity to pull him in one particular direction. He can only guide himself by the same means as the spacecraft itself – by rocket propulsion. So when astronauts do leave their spacecraft …

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