In How to know, about science and technology series we will provide you information about science and technology, We are in making part of series and every part will contain 8-10 scientific questions and answer !
HOW IS CONCRETE MADE?
Concrete is made by mixing gravel or small stones, sand and cement together with water. These materials are placed in a revolving concrete mixer, or they can be mixed together with a spade. The concrete is a paste that sets to form a hard material. It is used in building to make floors and walls, as well as roads, bridges and dams.
Most concrete is made in a concrete mixer, which revolves to turn the ingredients over and over so that they mix thoroughly.
HOW ARE SKYSCRAPERS BUILT?
Skyscrapers are tall buildings that A tower in the air. First, holes are dug in the ground so that the skyscraper is firmly fixed in place by its underground foundations. Then a high frame is built up from the foundations. Finally, walls and floors are fixed to the frame.
If the ground is firm, the foundations are wide so that they will spread the weight of the building and they do not go very deep. If the ground is not very firm, deep shafts of concrete are driven into the ground to anchor the skyscraper firmly,
HOW ARE TUNNELS BUILT?
Many tunnels are dug with tunnelling machines called moles. At the head of the mole, rotating cutters dig out the rock or soil, which is carried away along a conveyor belt. Powerful jacks act like springs to force the mole forward as it removes the rock and soil ahead.
As the mole edges forward through the ground, engineers fix lining panels into place to form the walls of the tunnel. For power and safety, the mole is driven by electric motors and hydraulic jacks.
HOW ARE BRIDGES BUILT?
Most bridges rest on supports called A piers. A wall is built in the river to keep out the water, and the piers are fixed in the bed of the river. Then the bridge is built on the piers. When it is finished, some of the piers may be taken away. Suspension bridges are built by fixing cables across a river from high towers on each side. The road is then hung from the main cables.
Long bridges need to be supported between the piers that hold them up. Arches carry a bridge by transferring its weight to the supports at each end of the arches.
HOW DOES A ROAD DRILL WORK?
Road drills are used to break through the road surface and dig up the road, The drill has a strong blade like a chisel that strikes the road many times a second. It is driven by compressed air piped to the drill from a compressor.
Road drills are also called pneumatic drills because they work on compressed air.
HOW ARE ROADS BUILT?
To build a road, engineers first A make the ground level. Then they construct a base of stones or gravel, on which they put a layer of concrete or macadam (crushed rock mixed with clay or tar). Finally a layer of tar called bitumen or asphalt is usually spread on top. The road builders also make drains at the side of the road to carry away rainwater.
Roads in towns are generally made of gravel and macadam and surfaced with asphalt and chippings. These roads can be easily dug up to get to the service pipes beneath.
HOW IS LEATHER MADE?
Real leather is made from the hides or skins of animals. Cattle hides are used to make most leather. Other animals that provide leather include pigs, sheep, goats and also sharks and snakes. To make leather, the hair or fur is removed and then the hides or skins are tanned to stop them from rotting.
Hair or fur is removed from the hides or skins by soaking them in lime solution and scraping them.
After dyeing, the leather is treated with oil or grease to make it flexible.
HOW IS CLOTH WOVEN?
Much cloth is made by weaving A threads together. A loom is used for weaving Lines of threads called warp threads move up and down in the loom. In between each movement, a shuttle pulls another thread called the weft between the warp threads. This action weaves the warp and weft threads together.
The warp threads are wound on a roller called the warp beam. They then pass through holes called eyes in frames of wires called heddles. In this way, the weft thread passes alternately above and below the warp threads, weaving a pattern.
HOW DOES A ZIP FASTENER WORK?
Metal zips have lines of tiny teeth, A while plastic zips contain small loops on each side. When you pull the slide of the zip fastener up, it pushes the teeth or loops together.
Beneath each tooth in a metal zip fastener is a small space. The slide is narrow at the bottom so that it forces the teeth together as you pull up the zip. The teeth on one side fit between the teeth on the other side.
As the slide moves down, a divider at the top of the slide pulls the teeth apart, Plastic zips have two spiral coils instead of lines of teeth.
HOW IS POTTERY MAD?
Pottery includes containers like A bowls and mugs and objects like tiles that are all made of clay. The pots and other articles are first formed in soft wet clay. Then the pottery is heated in a kiln.
Before the pottery is fired in the kiln, it is dried. Then a glaze may be added. When the glaze is fired, it produces a shiny coating on the pottery.
The finest pottery is called porcelain or China.
Also Read –
- Science And Technology Question & Answer – Part 1
- Science And Technology Question & Answer – Part 2
- Science And Technology Question & Answer – Part 3
- Science And Technology Question & Answer – Part 5
- Science And Technology Question & Answer – Part 6
- Science And Technology Question & Answer – Part 7
- Science And Technology Question & Answer – Part 8
- Science And Technology Question & Answer – Part 9
- Science And Technology Question & Answer – Part 10
- Science And Technology Question & Answer – Part 11
- Science And Technology Question & Answer – Part 12