Question

Человек, бегущий по движущемуся эскалатору метро поднимается наверх за 1 мин 20 с, а бегущий по неподвижному эскалатору за 2 мин. Какое время ему понадобится, чтобы подняться наверх по движущемуся эскалатору, если он будет неподвижно стоять на ступеньке​

Answer 1

Ответ:

3 мин 30 сек

Пошаговое объяснение:

Answer 2

Calculation of Time Required to Ascend the Moving Escalator

To calculate the time required for a person to ascend the moving escalator while standing still, we need to consider the time it takes for the person to ascend the escalator when it is stationary and the time it takes for the person to ascend the escalator while running.

According to the given information: - The person takes 2 minutes to ascend the stationary escalator. - The person takes 1 minute and 20 seconds (or 1.33 minutes) to ascend the moving escalator.

Let's assume that the speed of the escalator is v and the speed of the person running is u.

When the person is standing still on the moving escalator, their effective speed will be the sum of the escalator's speed and their own speed. Therefore, the effective speed can be calculated as v + u.

To find the time required for the person to ascend the moving escalator while standing still, we can use the formula:

Time = Distance / Speed

The distance covered by the person on the escalator remains the same in both cases, as the escalator is moving at a constant speed. Therefore, we can equate the distances covered in both scenarios:

Distance covered on the stationary escalator = Distance covered on the moving escalator while standing still

Let's denote the distance covered on the stationary escalator as d.

Using the formula for time, we can write the equation as:

d / (v + u) = d / u

Simplifying the equation, we get:

1 / (v + u) = 1 / u

Cross-multiplying, we get:

v + u = u

Simplifying further, we find:

v = 0

This implies that the speed of the escalator is zero, which contradicts the given information that the person takes 1 minute and 20 seconds to ascend the moving escalator.

Therefore, based on the given information, it is not possible to determine the time required for the person to ascend the moving escalator while standing still.

Please note that the given information may be incomplete or there may be some other factors that need to be considered to accurately determine the time required.