Les ondes, comme phénomène, sont omniprésentes et familières, mais leur constitution comme phénomène physique pose des difficultés bien connues. dues à leur nature pour ainsi dire insaisissable : quelque chose se déplace, qui contient de l'information et de l'énergie,mais ce n'est pas de la matière. Comment le caractériser?Quelles grandeurs physiques lui associe-t-on?Quels sont les comportements génériques des ondes? dans cette  première approche du phénomène.    

This lesson presents an overview of how plants are propagated. Upon completion of this unit students will know how to propagate plants both sexually and asexually. 

Published by the UC Santa Cruz Center for Agroecology and Sustainable Food Systems, the 600-page manual covers practical aspects of organic farming and gardening, applied soil science, and social and environmental issues in agriculture. Units contain lecture outlines for instructors and detailed lecture outlines for students, field and laboratory demonstrations, assessment questions, and annotated resource lists. Although much of the material has been developed for field or garden demonstrations and skill building, most of the units can also be tailored to a classroom setting.The training manual is designed for a wide audience of those involved in teaching farming and gardening, including colleges and universities with programs in sustainable agriculture, student farms or gardens, and on-farm education programs; urban agriculture, community garden, and farm training programs; farms with internships or apprenticeships; agriculture extension stations; school gardening programs; organizations such as the Peace Corps, US AID, and other groups that provide international training in food growing and ecological growing methods; and master gardener programs.

This activity is a gentle introduction to modeling via differential equations. The students will model the rate at which the word jumbo has propagated through English language texts over time.