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Speed necessary for the space station to stay in orbit.
Speed necessary for the space station to stay in orbit.
In this lesson you will learn that:
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.
This YouTube video investigates the structure and composition of the sun.
These four short online lessons cover the following:
This online resource investigates the internal structure, outer layers and surface features of the sun.
In this lesson you will learn about the following forms of renewable energy sources:
In this unit you will:
This online resource explores the terrestrial, or inner, planets - the planets closest to the sun: Mercury, Venus, Earth and Mars.
This online tutorial will provide you with some guidelines on how to interpret both topographic and geologic maps.