The educational resource shows a visual about the principle of superposition: when we talk about systems with more than two bodies, we have to bear in mind the Principle of superposition of forces: the force exerted by one body on another is independent of that exerted by the rest.

The educational resource shows a visual about the shape of galaxies: what causes the variety of shapes among galaxies? Some are spiral galaxies, others are elliptical or spherical.

The educational resource shows a visual about the planets: in addition to our planet, there are another eight planets travelling around the sun.

The educational resource shows a visual about the Milky way: you can manipulate our galaxy in the following visual to see its characterstics.

The educational resource shows an interactive animation about the mechanical equivalent of heat.

The inclined plane concept. With an inclined plane we can understand what forces are acting on the bodies resting on surfaces.

The educational resource shows an interactive animation about the heating curve: when a body is heated, its temperature increases until there is a change of state; while the change takes place, the temperature remains constant.

Relation between the power consumed and the supplied one for the generator.

The educational resource shows an interactive animation about the second law of thermodynamics for heat engines: it is not possible to achieve perpetual motion based on continuous reciprocal conversion between two forms of energy.

The educational resource shows an interactive animation about the first law of thermodynamics. The first law of thermodynamics establishes that energy is distributed in different ways, but it is not created or destroyed.

The educational resource shows how the energy is the capacity to produce changes in the environment by doing work or transferring heat. This means that when a body transfers heat or does work, its energy decreases.

The educational resource shows a visual that represents a capacitor, a system made up of two conducting plates with equal charges, but with opposite signs, separated by an insulator or a vacuum. Inside it the intensity of the field is approximately uniform, equal at all points.

In the following visual you can observe how the rotational axis of the earth is inclined; when the North Pole is furthest from the sun, the South Pole is nearest the sun and vice versa.

The following visual explains the precautions that should be taken into account when dealing with electricity

The educational resource shows a Flash animation about the greenhouse effect The Earth is an open material system, because it interchanges matter and energy with outer space.

The study of matter allows us to encompass the known universe in a range of sizes and distances with lower and upper bounds.

The educational resource shows an interactive animation about tempereture scales: there are various ways of expressing what the temperature of a body is. Each system is known as a temperature scale.

Telescope: optics and resolution range. Amateur astronomy is an enjoyable and educational passtime. If at any time you are able and want to get an astronomical telescope you should first find out about its possibilities.

The following visual which simulates a telescope can help you answer which telescope is better.

Telescope elements and the invention of the telescope