Effet électrostatique / Electrostatic effect – Electricité année 9

L’électrostatique est un chapitre de Physique qui n’est pas commode.

Note: If you are in Science grade 9, don’t leave the page before watching the videos at the end of this post because they are in English and I really recommend them.

En effet, l’effet électrostatique est observé tous les jours, par la charge qu’on reçoit quand on ouvre la porte de voiture de l’extérieur après un trajet quand le temps est sec. On l’expérimente quand on fait briller une table (soit ça n’arrive pas forcément souvent a mes étudiants), mais tous ceux avec des longs cheveux l’expérimentent quand on approche avec un peigne en plastique sec. On le constate quand on colle un ballon à un mur pour décorer. On l’expérimente le moins possible quand il y a orage et des éclairs dans le ciel. Quand un hélicoptère viendra vous sauver en haute mer, il faut que la nacelle touche l’eau avant que vous ne montiez dedans sinon vous serez électrocuté par la charge électrostatique que l’hélicoptère a pris en volant dans le ciel. Quand un avion atterrit, la première chose quoi fait est de mettre sa charge électrostatique à la terre car le caoutchouc des roues l’isole de la terre.

Grosso modo: quand on frotte quelque chose, soit on retire des électrons, soit on en pose.

​Tendance à attirer les électrons
​Plastique
​Or
Soufre
Caoutchouc
​Ébonite
​Paraffine
​Coton
​Papier
​Soie
Poils de chat
​Plomb
Laine
​Verre
​Acétate
​Fourrure
​​Tendance à donner les électrons

Donc la fourrure donnera des électrons à la laine par exemple, ou la soie donnera des électrons au caoutchouc. A la limite, la fourrure pourra donner des électrons au plomb (la fourrure deviendra chargée positivement et le plomb négativement), et le plomb à son tour pourra donner des électrons au coton (le plot deviendra positif, et le coton négatif).

Regardez ces vidéos: les 3 premiers sont d’un professeur extraordinaire présent sur YouTube et bozemanscience.com.




Year-round School – Advantages and Consequences

Today I am giving some thought to a year-round school: its advantages and disadvantages. These types of schools already exist, but are still often based on set vacation dates and splitting students by age. My suggestion is a year-round school that has no specific holidays or schedule and that would go hand in hand with the idea of the “One World Classroom” that I’ve talked about previously. I’ll use bullet form to go back to this work at another time. Of course I would be very interested to hear your thoughts.

Advantages to Parents (the tax payer)

  • Parents would be able to have full time professional work without constantly looking for quality day care during prodays and holidays.
  • Parents would be able to collect their children when they are on their way from work, not at 3pm in the middle of the afternoon.
  • Parents would be able to have quality time with their children without running here or there for extra classes: art, sport, scouts – because these classes would be integrated within the school. Also there would be no homework.
  • Parents would be able to take their holidays as a family together without the constraint of school holiday dates.

Advantage to Teachers

  • Teachers would have a job year round.
  • Professional development days would not require the students to stay home.
  • Like the students, teachers would be able to take their holidays at a time convenient to them, like in most other jobs.
  • Teachers would not note every year that students forget all they have learned over the summer, so the job would be more fulfilling.
  • Teachers would not need to hold the attention of a whole class, because they would only need to teach very small groups.
  • Distance Learning would be part of direct learning; the switched classroom would be the norm with a decrease in stress.

Advantage to Students

  • Students would be more relaxed because of the variety of activities in school. According to the author Salman Khan in the “One World Classroom”, academics could be reduced easily to only two hours per day.
  • Students would not need to learn again what they had already done the year before.
  • Each student would be an individual, and not a student, part of a class.
  • Students would be able to explore different subjects not included today in school such as dance, crafts, sea related sports, professional trades such as cooking or piping, millwright, or weaving.
  • Social board games would be part of teamwork development
  • Debate would be encouraged to become critical thinkers.
  • Students could progress in subjects they feel like exploring with less rigidity that in an age cohort system.
  • Students would feel an accomplishment every time they mastered a concept. This would have to be somehow formalized.
  • The possibility for older students to explore actual jobs during the day, and to get professional internships.

Disadvantage to Parents

  • Change: always stressful

Disadvantage to Teachers

  • Change: always stressful
  • Teachers would no longer be the only professionals in a school. There would be aids, and tutors. There could also be professionals come to share their knowledge from work.
  • Teachers would not rule, but be part of an educating team including artists and athletes.

Disadvantage to Students

  • Students would not feel that they ever reach an end. They could feel like in a never ending tunnel.
  • Learning would change from being a set course with a beginning and an end, and become life long learning.
  • Students would miss the high before going away for the Summer holidays
  • Students would miss the feeling of accomplishment when ending a level before going on to the next

Consequences: nothing short of a revolution!