Marta

Readers won't have to disassemble their favorite toys to discover what makes them work. This book explores electric, magnetic, and motion-powered toys from design to function. It introduces readers to the six simple machines and explains how they use force and motion to do work. Not every toy is a technological marvel. Readers learn about time-honored favorites including the rocking horse, Slinky, and rattles.

The story of Paul Revere, who rode from Boston to Lexington and Concord to warn the colonists that the British army was coming. In graphic novel format.

With simple examples that are easy to relate to, this basic review of some of the building blocks of economics will help readers easily grasp the concepts. With language that is conversational without being too casual, readers are engaged throughout as they learn about not only these basic concepts but how they fit into the whole economic scheme of things, such as where goods come from. Readers will learn about the three factors of production, as well as what happens when resources are lacking and how that influences the entire economy.

Se trata de una pregunta que nos inquieta solo de pensarla, tan profundamente dependen nuestras vidas y sociedades del mundo científico-tecnológico de la electricidad. Entre los grandes protagonistas de ese mundo, destaca un serbio que después de estudiar ingeniería en Graz (Austria), emigró en 1884 a América, instalándose en Nueva York; un serbio de imaginación y habilidades descomunales, un excéntrico sin miedo a lo desconocido, que gozaba montando espectáculos para promover sus inventos: Nikola Tesla (1856-1943). Es difícil apreciar cuánto debemos a sus inventos: sus ideas y...