Science & Mathematics Questions & Answers

A tree never permanently stops growing as long as it lives. But in most countries each year’s growth is ended during the cold and dry season. The annual period of growth depends on the climate. In most tropical regions a tree may grow continuously. Every period of growth is marked by an annual ring. This ring takes the form of …

A forest becomes petrified or turned to stone under certain conditions, through the action over the centuries of water containing large quantities of minerals. Tree trunks buried ages ago under mud, sand or volcanic ash have been gradually transformed as water seeped into the empty cells of the decaying wood, filling them with mineral matter and preserving every detail of …

A car uses overdrive when it is traveling at high speed over long distances. Overdrive, or cruising gear, is a device which enables the engine to run at a relatively low speed even when the vehicle is traveling fast. All internal combustion engines fitted in vehicles need some kind of gearbox because their efficiency at low speeds is poor. The …

Plants breathe oxygen and carbon dioxide. In daylight they produce their own food at the same time by a process known as photosynthesis. During this process the plants release more oxygen into the atmosphere than they breathe in. The effect of the plant’s feeding and breathing system is that they exhale oxygen during the night. This is the reason for …

The world’s first electric locomotive was designed by the German scientist Werner von Siemens. It was shown at an international trade exhibition in Berlin in 1879. A special track was built for the locomotive, which hauled up to thirty visitors at a time around the exhibition. One of earliest electric railway, in England was Volk’s Electric Railway, built along the …

The first talking movies were produced in France before 1900 by Leon Caumont. They were short films, starring great performers such as Sarah Berhard, in which the movie pictures were synchronized with a gramophone record. By 1912 Eugene Lauste had discovered the basic method for recording sound on film, while Thomas Edison produced several one-reel talking pictures in the United …

Regular mail coaches began to run in England in the 1780s. Armed guards travelled on them to protect them from highwaymen. By 1800 regular stage coach services were running between all the big towns and those carrying mails ran to a fast timetable. ‘Fast’ meant an average of 8 km an hour.

Rio Grande in Spanish means big river. Two different rivers bear the above name: the first is the river flowing through the eastern part of Jamaica, and the second, the river originating in the US and flowing through the southern United States and Mexico. Rio Grande of Jamaica is the largest source of fresh water in Jamaica and provides water …

In China and Japan eel is not only eaten as food but is also known for its medicinal properties. Ancient Koreans believed eel helped relieve fatigue and sexual debility. Eel skin or kadaagel also has medicinal properties. Its tightening ability makes it useful as a type of brace to relieve sprains.

The doomsday vault is a Noah’s Ark of sorts which would store samples of the world’s important seeds. It was inaugurated at Longyearbyen, Norway. The vault is a trident-shaped tunnel bored into the permafrost of the Arctic mountain range. It comprises three cold chambers and can hold 4.5 billion batches of seeds from the main crops. This is to ensure …