14. Sahana wants to test the properties of a fabric which can be used to prepare a rain
coat. She has taken four flexible materials of the same size and thickness and
fully dipped into four containers, each contaning 100 ml of water and results
were tabulated.
[ ]
Material
1
II
IV
O
Water left in container 40 ml
95 ml
20 ml
75 ml
Based on the above results, which fabric can be used to prepare a rain coat.
1) Materiall
2) Material II
3) Material III
4) Material IV
Answers
Answer:
Raincoats are jackets made of fabric that is specially treated to repel water. In 1836, Charles Macintosh invented a method for combining rubber with fabric, which was used in the first modern raincoats. Because of his inventions, all raincoats are called Mackintoshes or Macs by those in Great Britain. Most modern day raincoats are inspired in one way or another by Macintosh's brainchild.
Today there are many kinds of raincoats made of all types of fabric. An all-weather raincoat has a removable lining so it can be worn in any weather. Fold ups are foldable and usually made of vinyl. Vinyl raincoats are made of vinyl or of fabric that has a vinyl finish. Trenchcoats are worn by both men and women, and are often made of lightweight cotton/polyester fabric.
What is important to raincoat manufacture is efficient waterproofing. There are two important qualities: absorption (how much water can be soaked by the fabric) and penetration (the amount of water that can sink into the fabric). Raincoat fabrics are either absorbent or repellent. The best raincoats are made of tightly woven fabric.
Read more: http://www.madehow.com/Volume-6/Raincoat.html#ixzz6tldjaEay