Kirchhoff's Voltage Law says if you travel around any loop in a circuit, the voltages across the elements add up to zero. Created by Willy McAllister.
Lenz's Law - seeing that the magnetic field induced by a current induced by a change in magnetic flux (Faraday's Law) counteracts the change in flux.
See how a wire carrying a current creates a magnetic field. Created by Sal Khan.
Sal shows how to determine the magnetic force between two currents going in opposite directions. Created by Sal Khan.
Sal shows how to determine the magnetic force between two currents going in the same direction. Created by Sal Khan.
Sal shows how to find the size and direction of the magnetic force using F=qvB and the right hand rule. Created by Sal Khan.
Sal derives the formula F=ILB to determine the force on a current carrying wire. Created by Sal Khan.
Sal does an example problem to determine the size and direction of the magnetic force on a proton moving through a magnetic field. Created by Sal Khan.
Sal determines the radius of the circle traveled by the proton in the previous example by using the formula for centripetal acceleration. Created by Sal Khan.
In this video David explains how to find the magnitude of the electric field created by a point charge and solves a few examples problems to find the electric field from point charges. Created by David SantoPietro.
Nuclear binding energy is the energy required to split an atom’s nucleus into protons and neutrons. Mass defect is the difference between the predicted mass and the actual mass of an atom's nucleus. The binding energy of a system can appear as extra mass, which accounts for this difference. Created by Jay.
The Maxwell-Boltzmann distribution describes the distribution of speeds among the particles in a sample of gas at a given temperature. The distribution is often represented graphically, with particle speed on the x-axis and relative number of particles on the y-axis. Created by Sal Khan.
In this video David solves a few exmaple problems involving concave and convex mirrors using the mirror equation and magnification equation.
A few more examples of exponential decay. Practice calculating k from half-life, and calculating initial mass. Created by Sal Khan.
David explains some of the common misconceptions in dealing with Newton's Third Law. He also shows how to correctly and reliably identify Third Law force pairs. Created by David SantoPietro.
Clarification of, and more thoughts on, the Bernoulli's equation example problem where liquid exits a hole in a container. Created by Sal Khan.
See how there's actually constructive (rather than just destructive) interference at some points on the screen. Created by David SantoPietro.
Some examples of using the thin lens equation with multiple lenses. Created by David SantoPietro.
In this video David solves an example problem to find the net electric field created by multiple charges at a point in between them. Created by David SantoPietro.
In this video David solves an example 2D electric field problem to find the net electric field at a point above two charges. Created by David SantoPietro.