Question

Эскалатор метро поднимается со скоростью 1 м/с. Может ли человек, находящийся на нём, быть в покое в системе отсчёта, связанной с Землёй?1)Может, если движется в противоположную сторону со скоростью 1м/с.2)Может, если движется в ту же сторону со скоростью 1м/с.3)Может, если стоит на эскалаторе.4)Не может ни при каких условиях.

Answer 1

Ответ 1) правильный. Если он пойдет в сторону, противоположную движению эскалатора с той же скоростью, что и эскалатор, то скорости друг друга вычтут, и человек относительно Земли будет покоиться

Answer 2

Can a person on an escalator in a metro system be at rest in a reference frame connected to the Earth?

In order for a person on an escalator in a metro system to be at rest in a reference frame connected to the Earth, there are a few conditions to consider:

1) Moving in the opposite direction with a speed of 1 m/s: If the person is moving in the opposite direction of the escalator with a speed of 1 m/s, it is possible for them to be at rest in a reference frame connected to the Earth. In this case, the person's speed relative to the Earth would be zero, canceling out the speed of the escalator.

2) Moving in the same direction with a speed of 1 m/s: If the person is moving in the same direction as the escalator with a speed of 1 m/s, they would not be at rest in a reference frame connected to the Earth. The person's speed relative to the Earth would be the sum of their speed and the speed of the escalator, resulting in a non-zero value.

3) Standing still on the escalator: If the person is standing still on the escalator, they would not be at rest in a reference frame connected to the Earth. The person would still be moving with the speed of the escalator, even though their own speed relative to the escalator is zero.

Therefore, the only scenario in which a person on an escalator in a metro system can be at rest in a reference frame connected to the Earth is when they are moving in the opposite direction with a speed of 1 m/s.