Understanding the differences between the dot and cross products. Created by Sal Khan.
Learn how to draw rectangles and lines with code (JavaScript and ProcessingJS).
Learn more www.pixarinabox.org.
Remember the relationship between current and voltage in an inductor and capacitor with the help of ELI the ICE man. Created by Willy McAllister.
Earth ƒ??was formed approximately 4.6 billion years ago, likely as the result of a supernova (star explosion). The debris from this explosion began to collapse in on itself due to gravity, forming the sun. Gravity continued to draw the remaining particles together, clumping them into larger bodies, ultimately forming Earth and the other planets in our solar system. Created by Sal Khan.
Communities are dynamic and change over time, and we can observe this process with particular clarity after a disturbance or on new land. Learn about primary and secondary succession, as well as pioneer species. Created by Sal Khan.
Ecology is the study of how living things interact with each other and their environment. This includes living things (biotic factors) and non-living things (abiotic factors).
Introduction to ecosystems. How land ecosystems are classified into biomes.
Overview of this lesson.
Introduction to the egg, sperm, and fertilization. Created in collaboration between the Association of American Medical Colleges and Khan Academy.
David explains what it means for a collision to be elastic or inelastic. Created by David SantoPietro.
Current is the flow of charge. We measure current by counting the amount of charge passing through a boundary in one second. Created by Willy McAllister.
In this video David explains why physicists came up with the idea of the electric field, how it's useful, and explains how the electric field is defined. Created by David SantoPietro.
The direction of an electrical field at a point is the same as the direction of the electrical force acting on a positive test charge at that point. For example if you place a positive test charge in an electric field and the charge moves to the right you know the direction of the electric field in that region points to the right. Created by David SantoPietro.
Sal shows that there will be a net torque on a loop of current in a wire. Sal shows that this net torque will cause the loop to rotate. Created by Sal Khan.
Sal shows that a commutator can be used in order to keep the loop of wire rotating in the magnetic field. Created by Sal Khan.
Sal finishes the explanation of how a commutator will allow a loop of wire to continue spinning in a magnetic field, thereby allowing it to work as an electric motor. Created by Sal Khan.
David explains electric potential (voltage). Created by David SantoPietro.
Introduction to electric potential energy. Created by Sal Khan.
In this video David explains how to find the electric potential energy for a system of charges and solves an example problem to find the speed of moving charges. To see the calculus derivation of the formula watch this video. Created by David SantoPietro.