Lecture 6
No description yet. This curated deck is ready for daily study.
Card preview (18)
What does (Charles Augustin de) Coulomb’s law say?
It is the nature of electrical forces. If two electrically charged objects move farther away from each other the force between them gets smaller. The size of the force depends on the product of the charges of the two objects
What is the equation written and physical for Coulomb’s law
The magnitude of the electrostatic force between any two electrically charged objects is proportional to the product of their charges divided by the square of the distance between them. Force (N) = k (coulomb’s constant of 8.99 x 10^9 newton-meter^2 /coulomb^2) times x times the first unit for charge q1 times q2 divided by distance squared
Force is related to?
charge and distance
Every charged object exerts force on its surroundings to create an?
electrical field
What is the mineral that shows that magnetism is naturally occurring?
Magnetite
What did William Gilbert say about magnetism?
Every magnet has two poles, making it a dipole, where like magnetic poles repel and unlike poles attract. Says the Earth is a giant magnet with the North Magnetic Pole near the North pole allowing for its rotational axis
What does a magnetic field look like?
It is a curving field pattern of imaginary lines where the number of lines in a given area measures the strength of the magnetic field. It will be stronger near the poles
How is the Earth like a giant magnet?
The compass needle always points North because of the magnetic field created that protects us from cosmic space rays that starts at the south magnetic pole and loop up to the north magnetic pole
How and where is the Earth’s magnetic field generated?
In the outer core that is made up of 85% liquid iron, that moves creating an electrical current
What is declination?
The angle between where a compass needle points and the geographic/rotational north pole, the deviation of the compass from true north. This will change based on your location
What is inclination?
The angle of the magnetic field with respect to the horizontal (or the dip of the magnetic field) where it is 90 degrees at the poles and 0 at the equator
What does inclination look like presently, vs in the past?
Currently, the magnetic field in the north point is downward, and the magnetic field in the south point is upward. 800,000 years ago the magnetic field pointed up in the north and down in the south.
What is normal polarity?
a positive charge comes from the south and moves towards a negative north
What is paleomagnetism and what does it do?
The direction of Earth’s magnetic field can be seen in rocks as within lava there are particles of magnetite that will move before getting frozen in place when the lava cools.
How are magnetic fields used for navigation?
Microscopic organisms use magnetic crystal chains to know which direction they are moving, whether it is up or down, and birds, turtles, and some fish can detect the magnetic fields for migration.
What was Oersted’s accidental discovery?
He was a Danish prof who found that whenever an electrical current was flowing through a circuit a nearby compass would move. When he turned off the electric circuit the needle went back to pointing north.
How are electricity and magnetism related?
They are intimately related as magnetic field can be created by motions of electrical charges which led to the development of the electromagnet
Why can a monopole never exist in nature?
You can never get an isolated pole, and they do not exist in nature. The electrons in motion inside an atom create a current much like the electrical current in the loop of wire in an electromagnet. Both systems create a current flow that produces a magnetic field, meaning that you will always have a dipole because it exists at the atomic-scale current loop