FundamentalForces

The four fundamental forces of Nature are:

The four forces of nature are gravitation, electromagnetism, the strong nuclear force, and the weak nuclear force.

Gravitational; this is the weakest type of force and is experienced by everything that has mass. We have already studied this, and will remember that it is subject to the inverse square law. Any body with mass exerts an attractive force upon any other body. This force is noticed on earth because the mass of the earth is so big that we feel it.

When Newton saw the apple hit the ground, he realised that it was a phenomena that was not only experienced on earth but throughout the Universe. Every morsel of matter attracts every other body of matter, however the size of this attraction is quite small between small objects, the force between two bags of sugar (1kg) placed 1m apart is 0.000000000067 N, whereas the force between the bag and earth is 9.8 N. The reason the attraction toward earth is so big is due to the huge mass of the earth

We still cannot explain the how and why gravity happens

Electromagnetic;

this type acts between charged particles and are common in everyday life. force between charged particles. We have already studied this, and will remember that it is also subject to the inverse square law.

This force is best demonstrated by the effect of static charge, and on a common level this is not a huge force. Within the objects the force that holds them together is huge.

Strong nuclear forces

are "felt" by the hadrons and so they hold nuclear particles together. force binding nucleus, short range.

Leptons do not experience this force.

Weak nuclear forces

are felt by all particles (including leptons (electrons, positrons, muons), the particles that do not feel the strong force).

The weak nuclear force also acts over a small distance range (but longer than strong force)

All are “actions at a distance”. Gravitation and forces between charges are governed by an inverse square law, which is of unlimited range. Nuclear forces fall off much more quickly with distance and are negligible outside nuclear distances (10–15 to 10–14 m).

Fundamental forces Relative Strength

Gravitational force 1

Weak nuclear force 1025

Electromagnetic force 1035

Strong nuclear force 1038

The gravitational interaction between the particles at nuclear distances is so weak that it can be neglected, in comparision to the other forces.

this site explains it well http://homepage.eircom.net/~louiseboylan/Pages/Four_Forces.htm

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