Site for children


J. Perelman
"Entertaining physics". Book 2.
Chapter 2. Power. Work. Friction

IF THERE WERE NO FRICTION

You can see how diverse and sometimes unexpectedly appears friction in the surrounding environment. Friction is involved, and, moreover, is very significant, where we don't know. If the friction suddenly disappeared from the world, many natural phenomena proceeded would be in a completely different way.

Very colorful writes about the role of friction by French physicist Guillaume:

"We all happened to go in the ice: how much effort it took us to keep from falling as funny movements we had to do to survive! It forces us to recognize that typically the land on which we walk, has a precious property, by which we maintain balance without much effort. The same idea occurs to us when we go on the bike on the slippery pavement or when the horse is sliding on asphalt and falls. Studying such phenomena, we come to the opening of those effects that result from the friction. Engineers shall endeavour to resolve it in the cars and do well. In applied mechanics of friction is described as a highly undesirable phenomenon, and rightly so, but only in a narrow, specific area. In all other cases we should be grateful friction: it gives us the ability to walk, sit and work without fear that the books and the ink drops on the floor, the table will slide until you run into a corner, and the pen will slip from your fingers.

Friction is such a widespread phenomenon that we are, with rare exceptions, do not have to ask for help: it is the us itself.

Friction promotes sustainability. Carpenters level floor so that the tables and chairs remain where they were placed. Dishes, plates, glasses, put on the table, remain fixed without much effort from our side, if only it's not going on the boat while pitching.

Imagine that friction can be eliminated completely. Then no body, whether they be the size of a boulder or small as grains of sand, never held one on another: everything will slide and roll until you are on the same level. Don't be friction, the Earth would be a ball without irregularities, like liquid.

It may be added that in the absence of friction nails and screws slid least from the walls, not one thing it would be impossible to hold in the hands, no vortex would never have stopped, no sound did not stop, and would sound an endless echo, sustained reflected, for example, from the walls of the room.

Lesson, convincing us of great importance friction, gives us every time with ice. Caught it on the street, we find ourselves helpless and all the time you risk to fall. Here is a brief excerpt from a newspaper (December 1927):

"London, 21. Due to the strong icy street and tram traffic in London is noticeably difficult. About 1,400 people were admitted to hospital with fractures of the hands, feet and so on".

In a collision near Hyde Park three cars and two tram cars the cars were completely destroyed due to the explosion of gasoline..."

"Paris, 21. Sleet in Paris and its suburbs has caused many accidents..."

However, negligible friction on ice can be successfully used technically. Already ordinary Sani serve as an example. Even better testify to this so-called ice roads, which are arranged for removal of forest from logging to the railway or to items of alloy. On the road with the smooth icy rails, two horses pulling a sled loaded with 70 tons of logs.


Top - loaded sled on an icy road; two horses carrying 70 tons of cargo.
At the bottom of the icy road, And the track; B - snake; With - compacted snow; D - earth-base of the road.

Entertaining physics J. Perelman

 




System Orphus

SUPPORT THE SITE!

Did you like our site and you would like to support it? It's very simple: tell your friends about us!
Read MORE

  © 2014 All children