Task 2. Which of the parts is longer iron or aluminum, if their masses and areas are equal. (piron = - id2097930920230430 от НастяЛитвинюк 30.04.2023 12:01

Question

Физика: Task 2. Which of the parts is longer iron or aluminum, if their masses and areas are equal. (piron = 7800 kg/m), paluminum = 2700 kg/M )

НастяЛитвинюк · Accepted Answer

Дано:
S = 1500 м
V11 = 36 км/ч = 10 м/с
V12 = 27 км/ч = 7,5 м/с
V21 = 7,5 м/с
V22 = 10 м/с
Δt - ?

ПЕРВЫЙ велосипедист:
t1 = S / (2*V11) = 1500 / (2*10) = 75 c
t2 = S / (2*V12) = 1500 / (2*7,5) = 100 c
Общее время
t = t1 + t2 = 75 + 100 = 175 c

ВТОРОЙ велосипедист:
Пусть to - полное время второго велосипедиста
to / 2 - половина времени

Тогда
S1 = V21*to / 2
S2 = V22*to /2
S = S1 + S2 = (V21 + V22)*to / 2
to = 2*S / (V21 + V22) = 2*1500 / (7,5 + 10) = 3000 / 17,5 ≈ 171 c
Второй велосипедист БЫСТРЕЕ на 4 секунды (175 - 171)

Task 2. Which of the parts is longer iron or aluminum, if their masses and areas are equal. (piron = 7800 kg/m), paluminum = 2700 kg/M")

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