Don't miss the piglix.com special BONUS offer during our Beta-test period. The next 100 new Registered Users (from a unique IP address), to post at least five (5) piglix, will receive 1,000 extra sign-up points (eventually exchangeable for crypto-currency)!

* * * * *    Free piglix.com Launch Promotions    * * * * *

  • Free Ads! if you are a small business with annual revenues of less than $1M - piglix.com will place your ads free of charge for up to one year! ... read more

  • $2,000 in free prizes! piglix.com is giving away ten (10) Meccano Erector sets, retail at $200 each, that build a motorized Ferris Wheel (or one of 22 other models) ... see details

Force

Force
Force examples.svg
Forces are also described as a push or pull on an object. They can be due to phenomena such as gravity, magnetism, or anything that might cause a mass to accelerate.
Common symbols
F, F
SI unit newton
In SI base units 1 kg·m/s2
Derivations from
other quantities
F = m a

In physics, a force is any interaction that, when unopposed, will change the motion of an object. In other words, a force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F.

The original form of Newton's second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time. If the mass of the object is constant, this law implies that the acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object

Related concepts to force include: thrust, which increases the velocity of an object; drag, which decreases the velocity of an object; and torque, which produces changes in rotational speed of an object. In an extended body, each part usually applies forces on the adjacent parts; the distribution of such forces through the body is the so-called internal mechanical stress. Such internal mechanical stresses cause no accelation of that body as the forces balance one another. Pressure, the distribution of many small forces applied over an area of a body, is a simple type of stress that if unbalanced can cause the body to accelerate. Stress usually causes deformation of solid materials, or flow in fluids.


The four fundamental forces of nature
Property/Interaction Gravitation Weak Electromagnetic Strong
(Electroweak) Fundamental Residual
Acts on: Mass - Energy Flavor Electric charge Color charge Atomic nuclei
Particles experiencing: All Quarks, leptons Electrically charged Quarks, Gluons Hadrons
Particles mediating: Graviton
(not yet observed)
W+ W Z0 γ Gluons Mesons
Strength in the scale of quarks: 10−41 10−4 1 60 Not applicable
to quarks
Strength in the scale of
protons/neutrons:
10−36 10−7 1 Not applicable
to hadrons
20
Units of force
newton
(SI unit)
dyne kilogram-force,
kilopond
pound-force poundal
1 N ≡ 1 kg⋅m/s2 = 105 dyn ≈ 0.10197 kp ≈ 0.22481 lbf ≈ 7.2330 pdl
1 dyn = 10−5 N ≡ 1 g⋅cm/s2 ≈ 1.0197 × 10−6 kp ≈ 2.2481 × 10−6 lbf ≈ 7.2330 × 10−5 pdl
1 kp = 9.80665 N = 980665 dyn gn⋅(1 kg) ≈ 2.2046 lbf ≈ 70.932 pdl
1 lbf ≈ 4.448222 N ≈ 444822 dyn ≈ 0.45359 kp gn⋅(1 lb) ≈ 32.174 pdl
1 pdl ≈ 0.138255 N ≈ 13825 dyn ≈ 0.014098 kp ≈ 0.031081 lbf ≡ 1 lb⋅ft/s2
The value of gn as used in the official definition of the kilogram-force is used here for all gravitational units.

...
Wikipedia

1,000 EXTRA POINTS!

Don't forget! that as one of our early users, you are eligible to receive the 1,000 point bonus as soon as you have created five (5) acceptable piglix.

...