El ferrocarril transcontinental (The Transcontinental Railroad)

People today refer to the Midwestern and prairie states as flyover country. During the Civil War, crossing those areas was the biggest obstacle in uniting the East and West Coasts of our divided nation. An act of Congress in 1862 authorized the Central Pacific and the Union Pacific railroad companies to build a railroad that would link the coasts. Seven years later, on May 10, 1869, an overwhelmingly immigrant labor force completed the task when a rail line was join in Promontory, Utah. The states had become united at last.

Diseñado como respuesta al temario oficial del Curso de Orientación Universitaria, y como Manual de Iniciación para aquellos alumnos/as que cursen estudios de Física General en las Escuelas Universitarias. Una exposición teórica suficientemente profunda, complementada con una amplísima colección de problemas - unos, explicados y resueltos; otros, propuestos e indicada su solución - proporcionan un conocimiento directo de la materia y sus aplicaciones.

Tras asomarse al futuro y ver el negro panorama que espera a nuestro planeta, Natalia y Mayden deben concienciar a la gente de la importancia de colaborar entre todos para evitarlo. Gaia, la Tierra, no puede seguir soportando la desaparición de especies y la invasión de plástico. Pero los negacionistas, liderados por los youtubers Magufa y Camelo, van a tratar de evitarlo ridiculizándoles en sus vídeos. ¿Cómo serán capaces nuestros amigos de frenar la catástrofe medioambiental? Los autores cuentan con más de 14.500.000 suscriptores en YouTube.

"In this title, children explore the reasons why they may feel worried, how to recognize these feelings, and appropriate action to take when they feel worried."

Young readers may have heard about the benefits of using and making the most of their resources, but how does that factor into an economic discussion? This thorough discussion defines resources and describes the different types of resources and why some divide them into three categories and others choose four. The book also addresses the concept of scarcity, showing readers how, because all resources have their limits, it is important to use them responsibly and efficiently in a healthy economy.