Area of a Rectangle: 2 Videos
Video 1: Area of a rectangle
Video 2: Examples pertaining to areas of rectangles
Video 1: Area of a rectangle
Video 2: Examples pertaining to areas of rectangles
Video 1: Area of a triangle
Video 2: Examples pertaining to the area of triangles
Video 3: Common mistakes made when calculating the area of a triangle
Note: Click on the 'back button' to return to the VLE after watching each video
Introduction to magnetism: Wikipedia article that provides an overview of the concept.
The force that acts across the air gaps between magnets is the same force that creates wonders such as the Aurora Borealis. In fact, magnetic effects pervade our lives in myriad ways, from electric motors to medical imaging and computer memory. In this chapter, we introduce magnets and learn how they work and how magnetic fields and electric currents interact.
Electric charge comes in two varieties, which we call positive and negative. Like charges repel each other, and unlike charges attract each other. Thus, two positive charges repel each other, as do two negative charges. A positive charge and a negative charge attract each other.
How do we know there are two types of electric charge? When various materials are rubbed together in controlled ways, certain combinations of materials always result in a net charge of one type on one material and a net charge of the opposite type on the other material. By convention, we call one type of charge positive and the other type negative.