Results

How to solve for the horizontal displacement when the projectile starts with a horizontal initial velocity. We also explain common mistakes people make when doing horizontally launched projectile problems.

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.

• 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.

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

This 11 minute long YouTube video describes the various causes and types of water pollutants.

This YouTube video investigates what water pollution is and some examples and effects of water pollution.