Concept of radioactivity. Radioactivity is the property which certain substances have for emitting radiation.

A picture shows some transformations of energy. The energy from the sun passes to plants, to oil, to coal, to animals and to human beings; they take advantage of it by using the energy from oil, animals, coal, etc.

Friction concept

Concept of Waves in the sea. The waves on the sea or those which form on any surface of water, are a special instance of undulatory movement.

Concept of wavefront: wavefront is the locus of points characterized by propagation of positions of identical phase.

Concept of wave function: there is a mathematical function associated with every particle which behaves like the functions of other undulatory phenomena.

Concept of wave equation

Instrumento que mide el voltaje (caída de tensión o diferencia de potencial) entre los extremos de un elemento de un circuito eléctrico.

The voltmeter is an instrument which measures voltages (tensions or differences of potential) between both ends of an element in a circuit through which there is an electric current circulating.

Measure of the voltage. If you wish to measure the voltage in an electric circuit, you need a measuring device (multimeter)

La vida media representa el promedio de vida de un núcleo atómico de una muestra radiactiva.

Concepto de velocidad y masa de los electrones. Cuando sobre un tubo de rayos catódicos se sitúan un campo eléctrico y otro magnético, perpendiculares, puede estudiarse de manera cuantitativa las propiedades de los electrones: su velocidad, su carga y la relación carga/masa.

A particle which oscillates around a point of equilibrium, subject to a force proportional to the distance to this point, has a simple harmonic vibratory movement.

Concept of vectors: composition

Concepto de composición de vectores

Concepto de vector desplazamiento

Concepto de vector desplazamiento

El valor representativo de una serie de medidas es el que pensamos que más se aproxima al valor real de dicha medida.

El vector posición indica dónde está el móvil. La trayectoria marca la línea por la que ha pasado.

Vectors are a great help when you have to represent different physical magnitudes.