По ЗСЭ (закону сохранения энергии) максимальная высота будет в момент, когда вся кинетическая энергия перейдёт в потенциальную , то-бишь : Ек = Еп , где Еп = mgh отсюда h = Ек / mg = 200 / 0,5 *10 = 40 м
Т.к. полная механическая энергия не меняется в данной замкнутой системе , то на высоте 10 м будет и кинетическая и потенциальная энергия . Полная механическая энергия - максимальная кинетическая,либо потенциальная энергия. Ek max = Ek + Ep 200дж = mv^2/2 + mgh отсюда v = sqrt( 2*(Ekmax - mgh )/m ) = 24,5 м/c
— Are you alone at home. Jack?
— No, my dad isn't in but my mum is at home.
— (0) What is your father doing?
— My dad is taking part in a competition.
— Really? (1) What com petition is vour dad taking part in?
— A swimming competition. And my mum is watching a film
— (2) What film is she watching?
— 1 don:t know" And are your parents at home?
— Mum and dad have been at my grandmother's place for 2 days.
— Is your sister staying with you?
— Yes: she is.
— (3) What is your sister doing now?
— She is watching TV.
— (4) What programmes is she watching?
— A programme about music.
