4. a) Expliquer comment connecter des piles de 1,5 V afin d'obtenir une différence de potentiel totale de 9 V. b) Qu'arrivera-t-il au potentiel électrique de la batterie de 9 V si une des piles est inversée.

the answer is kevlar

the answer would most likely be c, because if it's a comical piece of information, it may likely not be true, if it's a site that allows anybody to edit the content, it could mean a five year old is typing the info, and if it's a tv show produced by a celeb, it may have a biased opinion.

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle