Resultaten

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

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.

• 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.

Other objects in the solar system are discussed in this online textbook viz. asteroids, meteorites, comets and dwarf planets.

This YouTube video explains how river basins are formed.

This YouTube documentary highlights the ecological and socio-economic importance of the Tana River Basin in Kenya.

Defining and comparing tension, weight, friction and normal forces using free body diagrams.

This 32 minute long YouTube video investigates the water contamination problems in Tanzania, with specific focus on Dar Es Salaam.