Results

These three short online lessons discuss asteroids, comets and meteors.

• Determine the variables that affect the strength and direction of the electric field for a static arrangement of charges.
• Investigate the variables that affect the strength of the electrostatic potential (voltage).
• Explain equipotential lines and compare them to the electric field lines.
• For an arrangement of static charges, predict the electric field lines. Verify the prediction using vector addition.

• Relate the electrostatic force magnitude to the charges and the distance between them
• Explain Newton's third law for electrostatic forces
• Use measurements to determine Coulomb’s constant
• Determine what makes a force attractive or repulsive

This online resource discusses the distribution of earth's water.

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.

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

A force diagram is a useful tool to help us visualise forces acting on an object and gives us informa- tion about the object’s motion. We often use force diagrams when solving calculations involving the forces acting on an object.

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

1. Define and explain what a force is
2. List and describe the main kinds of forces
3. Explain the effects of a force

• Predict, qualitatively, how an external force will affect the speed and direction of an object's motion.
• Explain the effects with the help of a free body diagram.
• Use free body diagrams to draw position, velocity, acceleration and force graphs and vice versa.
• Explain how the graphs relate to one another.
• Given a scenario or a graph, sketch all four graphs.