Exam Review Flashcards
Michael Faraday
How forces can be exerted remotely, and how to visualize fields
Isaac Newton
Universal laws of gravitation.
Charles Coulomb
Proportions of force, distance, and charge, Coulomb’s law, universal charges.
Henry Cavendish
Discovered the universal gravitational constant. (“G” constant)
Robert Millikan
Did the “oil drop” experiment. Discovered the Charge of a single electron. This value is called the elementary charge and accepted to be 1.60 x 10^-19 C
William Gerbert
Suggested that the Earth was a giant magnet.
Hans Christian Oersted
Discovered the relationship between electric fields and magnetic fields. Moving charges create magnetic fields.
Tesla
Discovered that the flux per unit area is proportional to the strength of the magnetic field.
1st Right hand rule
For any current carrying wire, you can find the direction of the magnetic field using the first right hand rule. Grasping the wire with your right hand and your thumb pointing in the direction of the conventional current (moving in direction of positive charge flow) , the fingers of your hand point in the direction of magnetic north
2nd Right hand rule
A coil of wire that creates continuous series of loops along an empty core is called a solenoid. If a current is run through the wire loops, an electromagnet is formed. The direction of the temporary magnet created is sound by the second right hand rule. When grasping the coils with the fingers of your right hand pointing in the direction of the conventional current your thumb will point in the direction of magnetic north.
Factors Affecting the strength of an electromagnet
- Increasing current
- Increasing the number of turns per unit length of the solenoid
- Using a soft-iron core within the solenoid
3rd Right hand rule
When a current carrying wire experiences a force in the presence of another magnetic field, the force can be found by using the third rule. Point the fingers of your right hand in the direction of the magnetic field. Point you thumb in the direction of the conventional current flow. The palm of your hand faces in the direction of the force acting on the wire.
How is gravitational field strength measured?
The strength of an Gravitational field is measured by taking a test mass and measuring the force at a specific location.
The attractive force between objects varies _______ as the distance ________
Inversely, Squared
Who discovered the relationship between distance and force?
Newton
Rules for diagramming field lines:
- Electric field lines are drawn away from positively charged objects and towards negatively charge objects.
- They meet the surface of an object at right angles
- They never cross
- They show the direction a massless, positive charge would follow if it were released in the electric field
- Spacing of field lines indicates relative strength of the field.
How is gravitational field strength measured?
The strength of an Gravitational field is measured by taking a test mass and measuring the force at a specific location.
In order for something to be charged what must happen?
There must be a deficit or surplus of electrons
Component Method: Ax + Bx = ? Ay + By= ? Cx + Cy=? tanθ=?
Ax + Bx = Cx
Ay + By= Cy
Cx + Cy=C (use pythagorean theorem)
(usually) θ=tan-1 (smaller vector ➗ larger vector)
[it must produce a decimal then use inverse tan)
Rules for diagramming field lines:
- Electric field lines are drawn away from positively charged objects and towards negatively charge objects.
- They meet the surface of an object at right angles
- They never cross
- They show the direction a massless, positive charge would follow if it were released in the electric field
- Spacing of field lines indicates relative strength of the field.
ΣF=?
acceleration=?
ΣF=ma
a=[ΣF➗m]
How do you read: 30km [E30°N]
30km, 30° north of east
Component Method: Ax + Bx = ? Ay + By= ? Cx + Cy=? tanθ=?
Ax + Bx = Cx
Ay + By= Cy
Cx + Cy=C (use pythagorean theorem)
(usually) θ=tan-1 (smaller vector ➗ larger vector)
[it must produce a decimal then use inverse tan)
Define: dynamics- Fg- Fe- Strong Nuclear Force- Weak Nuclear Force- Fn- Ff- Fa- Ft-
dynamics- study of forces
Fg- every object with a mass has an attraction to every other mass in the universe
Fe-the force that charged particles have on each other
Strong Nuclear Force-an attractive force that hold protons and neutrons in the nucleus of the atom acting in the 10e-15 m range
Weak Nuclear Force- the force exerted between all subatomic particles enabling a conversion of one quark into another
Fn- force that acts perpendicular to a surface
Ff-the force that opposes motion
Fa-force exerted by objects or people
Ft-the force exerted by a rope or string caused by objects or people
Basic ideas discovered by coulomb
- The force of attraction between two point charges is directly proportional to the product of their charges and 2. inversely proportional to the square distance between them.
Coulomb’s law
Fe=kqq/r2
How is the strength of an electric field measured?
The ratio of force divided by charge (Like gravitational fields)
What was millikan’s experiment
Millikan’s oil drop experiment: Found the charge of a single electron. Called elementary charge. Tiny oil droplets were suspended within an electric field and a gravitational field. Used stokes law.
How are auroras ( Northern lights) created?
They are created by the earth’s magnetic field. High energy particles from solar wind become trapped in the earth’s magnetic field. As these electrons oscillate along field lines, they collide with oxygen and nitrogen gas molecules exciting electrons in their outer shells, As they fall back down into heir lower orbits they emit light of different frequencies.
How do magnetic poles react with each other?
Like poles repel and opposite poles attract.
