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UNIVERSAL FORCES part I
4 Universal Forces:1)Electromagnetic2)Strong Nuclear3)Weak Nuclear 4)Gravitational
Electromagnetic Forces
Electromagnetic force is associated with charged particlesElectric & Magnetic forces = only forces to be able to do both attract and repel.
Electric Forces
Act on Charged ParticlesEX. Protons and Electrons
Opposite charges attractLike charges repel
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Magnetic Forces
Act on: Certain MetalsOn the poles of magnets On moving charges
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Poles of Magnets
Magnets have two poles North & South PoleOpposite poles attract each other—pull closerLike poles will repel each other—push apart
Two Nuclear Forces
1.Strong 2.Weak
Act within the Nucleus to hold it together
Strong Nuclear Force
Powerful force that Acts within the NucleusActs on Protons and Neutrons holding them togetherActs over short distance but is 100 time stronger that Electric Repulsion at same distance
Weak Nuclear Force
Another Powerful force that acts in the nucleus
It is associated with the decay of a nucleus (Breakdown) Is an attractive force that works over a short distance Affects all particles not just Protons and Neutrons.
UNIVERSAL FORCES part 2
Gravitational Force
Gravitational Force:Is the weakest of the Universal forces.It is a force that acts between any two (2) masses.Ex. Like the Earth and Moon, Ex. Like you and the textbook
Newton’s Law of Universal Gravitation
States: Every object in the universe attracts every other object.Gravity is Most Effective over long distanceEX. Gravity Keeps the Sun, Planets, Moons, Stars, Galaxies in orbits in the universe
Mass Determines the ForceGravitational force (GF) depends
upon mass and distance Larger mass =
larger gravitational force
GF Decreases as the distance increases
Earth, Moon & Tides
Centripetal Force – is center directed force.It causes continuous change in direction make it move in a circle.The moon’s mass creates a gravitational force on the Earth causing tides in the ocean.
Tides in the OceanWatch the
tide change with the
phase of the moon!!
Satellites in Orbit and UsesArtificial Satellites are kept in orbit by Centripetal Force Need to keep High speed or Earth Atmosphere will slow it down and it will reenter the atmosphere and burn up.Artificial Satellites are used for Weather,Telescopes, TV, Radio, Cell phone