Results

This online tutorial will explain the earth's shape and its hemispheres.

• Determine the variables that affect how charged bodies interact.
• Predict how charged bodies will interact.
• Describe the strength and direction of the electric field around a charged body.
• Use free-body diagrams and vector addition to help explain the interactions.

Video 1: What are frequency polygons?
Video 2: Examples of frequency polygons
Video 3: Further examples of frequency polygons

By the end of this unit you will be able to:

• Calculate measures of central tendency and percentiles on grouped data.
• Construct a frequency polygon.
• Construct a line graph.

This video explores how to find the mean from data in a table.

This video explores the histogram: which is one of the ways in which to present data.

Video 1: How to create a line graph based on data
Video 2: Examples of different line graphs
Video 3: Further examples of line graphs

This video explains how pie charts can be used to display data in a more 'user-friendly' way.

This video explains how to plot straight line graphs.

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.