Changes

As well as being added, forces can also be broken down (or 'resolved'). For example, a horizontal force pointing northeast can be split into two forces, one pointing north, and one pointing east. Summing these component forces using vector addition yields the original force.  Force vectors can also be three-dimensional, with the third (vertical) component at right-angles to the two horizontal components.

As well as being added, forces can also be broken down (or 'resolved'). For example, a horizontal force pointing northeast can be split into two forces, one pointing north, and one pointing east. Summing these component forces using vector addition yields the original force.  Force vectors can also be three-dimensional, with the third (vertical) component at right-angles to the two horizontal components.

The simplest case of static equilibrium is when two forces are equal in magnitude but opposite in direction.  This remains the most usual way of measuring forces, using simple devices such as [[weighing scale]]s and [[spring balance]]s. Using such tools, several quantitative force laws were discovered: that the force of gravity is proportional to volume for objects made of a given material (widely exploited for millennia to define standard weights); [[Archimedes' principle]] for bouyancy; [[Archimedes]]' analysis of the [[lever]]; [[Boyle's law]] for gas pressure; and [[Hooke's law]] for springs: all these were all formulated and experimentally verified before [[Isaac Newton]] expounded his three laws of motion.

The simplest case of static equilibrium is when two forces are equal in magnitude but opposite in direction.  This remains the most usual way of measuring forces, using simple devices such as [[weighing scale]]s and [[spring balance]]s. Using such tools, several quantitative force laws were discovered: that the force of gravity is proportional to volume for objects made of a given material (widely exploited for millennia to define standard weights); [[Archimedes' principle]] for bouyancy; [[Archimedes]]' analysis of the [[lever]]; [[Boyle's law]] for gas pressure; and [[Hooke's law]] for springs: all these were all formulated and experimentally verified before [[Isaac Newton]] expounded his three laws of motion.[http://en.wikipedia.org/wiki/Force]

 

for more see: [http://en.wikipedia.org/w/index.php?title=Force&action=edit]

[[Category: General Reference]]

[[Category: General Reference]]