Earth's rotations and revolutions
These two short online tutorials discuss how the earth rotates and then the earth's revolutions.
These two short online tutorials discuss how the earth rotates and then the earth's revolutions.
In the first URL, the YouTube video explains why earth has spring, summer, autumn and winter seasons. The second URL summarizes the key takeaway points.
Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.
An elaboration on how to use Newton's second law when dealing with multiple forces, forces in two dimensions, and diagonal forces.
Newton's second law of motion is F = ma, or force is equal to mass times acceleration. Learn how to use the formula to calculate acceleration.
We can analyse the arrows in a food web to identify producers, primary consumers, secondary consumers, and decomposers.
We can analyse the arrows in a food web to identify producers, primary consumers, secondary consumers, and decomposers.