Machine Parts

The air has weight just has any other material object has weight. Generally it cannot think air has weight because it cannot see but one can feels it weight and movement for a certain period when air blows around us or human body. However since the air is an object which have weight. The air is pulled toward the earth by gravitational attraction.  At sea level and at as average temperature a cubic foot of air weights about 0.08 pounds it seems a very small weight. However the blanket of air the surrounds the earth is many miles thick. It means that there are in effect many thousands of cubic feet of air, piled one on top of another all adding their weight. The real weight of the air or its under ward force amounts is calculated about 15 pounds which is found in sea level. Generally fish are subjected to much greater pressure more than 100,000 psi at several thousand feet down in the ocean.

Gravity is the attractive force which has all objects toward each others. One of the best example is stone which is hand fall from the earth to ground. The earth attract or love  the stones and it is pulled toward the earth. Another best example is a car being driven up a hilly area where a hood part of the engine power is being used to overcome the gravity. And raise the car against the gravitational attraction. As like as when a car can cost down a hill with the engine off cause of the gravitational attraction of the earth on the car. It is measure gravitational attraction with terms of weight. It has been fixed a object such as a scale where its weight is 12 pounds. Its mean that the object has enough mass for the earth to register that much pull on it.  It is gravitational love  or the pull of the earth that give san object its weight.

What is the snap method of timing?   What are it’s advantage and disadvantage?                             Snap method of timing:                                                                        Snap method of timing is one the stop watch timing element at which no time is lost,more accurate time is obtained.                          Advantage: 1.  ...