This video explains how two waves passing through each other interact through the process of superposition.

The resultant interference of waves at phase differences of 0⁰ or 360⁰ is constructive, they are additive.  Whereas phase differences of 180⁰ produce destructive interference, i.e., they cancel each...

This video begins by showing a demonstration of total internal reflection (TIR) through a semi-circular glass block.

It develops an understanding of TIR by showing that as the angle of incidence (θ_i) increases so too does the angle of refraction (θ_r).  Eventually, as  θ_i is...

This video shows how interference from two sound wave sources can produce both constructive (louder sound) and destructive (softer sound) interference patterns.  A demonstration using microwaves reinforces this idea. Microwaves are generated and passed through a double slit.  The resultant interference of waves is...

This film, from Twig World, explores some of the many ways to explore the Earth and its physical and 'human' features. The key points made in the film are: •Maps have been used by man throughout history to explain and navigate the world. •Traditionally, maps are two-dimensional drawings that use scale to map the...

This animation describes how Earth Observation satellites, such as METOP, allows us to forecast the weather and to measure changes in the climate and monitor natural disasters.  It also describes how the satellites are monitored by engineers on the ground to ensure they are functioning correctly.

A set of weighting scales is shown with a stack of cups on the scale. The cups are removed one by one in a fluid movement. The task is to graph the weight on the scales against time. 

Weight of cups video

A stack of cups is shown. Cups are added to the stack. Part way through a different style of cups is added, before the cups revert to the original style. The challenge is to graph the weight of the stack of cups against time.

Weight of stack 1 video

A stack of cups is shown. Cups are added to the stack. There is a variation in the rate at which cups are added. The challenge is to graph the weight of the stack of cups against time.

Weight of stack 2 video

Produced by the Wellcome Trust, these resources include an interactive evolutionary tree and a video of the Tree of Life. These materials will help students to find out more about the work of Charles Darwin and evolution. The resources contain:

Tree of life video: The video is a short...