Нагретый на солнце камень массой 4,3 кг бросили в воду. Чему равна удельная теплоёмкость камня, если при остывании на 1°C он отдал воде 3,3 кДж тепла? ответ (округли до сотых): Дж/(кг·°C).
Решение. Пусть встреча Шарика с последним вагоном произошла в точке D (рис.4).Треугольники АВС и АВD — прямоугольные. Тогда, используя теорему Пифагора, можно записатьРис. 4AB2=AC2−CB2=AD2−DB2,илиL2−l2=υ20t2−(at22−l)2.Отсюда выразим квадрат начальной скорости:υ20=L2t2+a2t24−al.Для того чтобы скорость υ0 была минимальной, необходимо, чтобы сумма L2t2+a2t24 принимала минимальное значение. Используем неравенство Коши:L2t2+a2t24≥2L2t2a2t24−−−−−−√=Laи получаемυ0=a(L−l)−−−−−−−√.Обратим внимание на то, что минимальная скорость достигается при условииL2t2=a2t24, или L=at22Значит, DC = СА = L, т.е. треугольник ACD - равнобедренный, иtgα=BDAB=L−lL2−l2√.Получили, что Шарику следует бежать под углом α=arctgL−lL2−l2√ к АВ со скоростью υ0=a−(L−l)−−−−−−−−−√.
Abdilda Tazhibayev was born in 1909 in Akmeshit (now Kyzylorda). Medium
one hundred
The Kipchak tribe Tory clan is descended from Bessary's grandfather. [1] [2] His father, Tazhibai, died in 1915 and was left in the care of his mother, Aimankul. Due to his condition, six-year-old Abdilda was taken to a suburb of Karaozek. Then the future poet lived until the age of thirteen with his mother Aimankul and uncle Daldabay
grows in upbringing. Young Abdilda's poems and literature
His mother and aunt also aroused his curiosity
will be the grandfather. Aimankul is fluent in Arabic and Persian
He was literate, open-minded, and cheerful.
He writes letters to Abdilda and teaches her literature. Abdilda's mother Aimankul, who later became a well-known folk poet and published a collection of poems, at the request of his father Daldabay, recited to the villagers the stories of the East and various Kazakh poems. Passionate, silent, silent
One of his listeners was Abdil. Later, in a small group, Abdilda would recite the stories and epics to his guests and villagers.
Abdilda Tazhibayev was born in 1909 in Akmeshit (now Kyzylorda). Medium
one hundred
The Kipchak tribe Tory clan is descended from Bessary's grandfather. [1] [2] His father, Tazhibai, died in 1915 and was left in the care of his mother, Aimankul. Due to his condition, six-year-old Abdilda was taken to a suburb of Karaozek. Then the future poet lived until the age of thirteen with his mother Aimankul and uncle Daldabay
grows in upbringing. Young Abdilda's poems and literature
His mother and aunt also aroused his curiosity
will be the grandfather. Aimankul is fluent in Arabic and Persian
He was literate, open-minded, and cheerful.
He writes letters to Abdilda and teaches her literature. Abdilda's mother Aimankul, who later became a well-known folk poet and published a collection of poems, at the request of his father Daldabay, recited to the villagers the stories of the East and various Kazakh poems. Passionate, silent, silent
One of his listeners was Abdil. Later, in a small group, Abdilda would recite the stories and epics to his guests and villagers.