IOM 2020, Блиц — Задача 25

The Blitz-contest of IOM-2020

Условие

For a heating element of a certain device, the temperature dependence (in $\mathrm{K}$) on the operating time was experimentally obtained:

$T(t) = T_0 + bt + at^2$

where $t$ is the time (in minutes), $T_0 = 1380\,\mathrm{K}$, $a = -15\,\mathrm{K/min^2}$, $b = 165\,\mathrm{K/min}$. It is known that if the heating element's temperature rises above $1800\,\mathrm{K}$, the device may break down, so it must be turned off.

Find the longest operation time after which the device must be turned off. Give your answer in minutes.

Fractional numbers can be entered either as a decimal fraction or as $m/n$.

Отговори

Решение

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Оригинал в Архива: iom-2020-blitz-tasks.pdf · официални решения: iom-2020-blitz-answers.pdf