The Four Forces of Nature A Brief Introduction

The forces of nature are responsible for providing the energy we used everyday! Recall…Energy comes from matter and energy and matter are reversible.

The forces of nature from weakest to strongest: Gravity > Weak Force > Electromagnetic Force > Strong Nuclear Weakest >>>>>>>>>>>>> Strongest

The Gravitation Force (Weakest) • Attractive force between ALL MASS in the universe • Unusual in that it is ALWAYS attractive • The weakest of all forces • Has infinite range (acts across the entire universe) • The “particle” that carries the force is called a graviton but is has never been found!!

The Weak Force • Acts at extremely small distances within the nucleus. • Responsible for radioactive decay of elements called betadecay. • Occurs when a neutron is changes into a proton or a proton changes into a neutron (very strange). This changes the identity of the element!! • Energy is released in the form of electrons and can do work.

The Electromagnetic Force • Most familiar to us. • Is the attractive force between positive and negative charges and the repulsive force between like charges particles. • Holds you together, the atoms of your chair, everything around you!! • Electricity, magnetism and light are all examples of this force. • Has infinite range • The photon is the “messenger” particle of this force.

What is making the iron fillings move away and towards the magnet spontaneously? Answer: photons are being exchanged between the magnet and the iron fillings. . you just can’t see them! http: //www. youtube. com/watch? v=Dn 6 VVZ 3 mrs 4&feature=related Is light magnetic? YES!! Another term for light is electromagnetic radiaton. See Video: http: //www. youtube. com/watch? v=WO 38 q. VDGgqw AGAIN…light, magnets and electricity are all one in the same force!!!!

The Strong Nuclear Force • This force works at extremely short range within the nucleus • Binds protons and neutrons together within the nucleus. • Keeps protons from repelling each other • If disrupted, the energy released is tremendous (example: Sun, nuclear bombs)

Summary of Forces: http: //www. youtube. com/watch? v=zdnmqb. L 4 jp 0 Lecture (10 minutes) on the four forces