Question

Пассажирский поезд идёт вслед за товарным.Скорость пассажирского поезда 64,3 км в час,а скорость товарного 42,7 км в час.Сейчас между ними 14,88 км.Какое расстояние было между ними 0,7 часа тому назад?

Answer 1

64,3-42,7=21,6 км/час скорость сближения
0,7*21,6=15,12 км прошли за 0,7 часа
14,88+15,12=30 км было между ними
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Answer 2

Problem Analysis

We are given the speeds of a passenger train and a freight train, as well as the initial distance between them. We need to calculate the distance between them 0.7 hours ago.

Solution

To solve this problem, we can use the formula: distance = speed × time.

Let's calculate the distance traveled by the passenger train and the freight train in 0.7 hours.

1. Distance traveled by the passenger train: - Speed of the passenger train: 64.3 km/h - Time: 0.7 hours - Distance = Speed × Time = 64.3 km/h × 0.7 hours = 44.91 km

2. Distance traveled by the freight train: - Speed of the freight train: 42.7 km/h - Time: 0.7 hours - Distance = Speed × Time = 42.7 km/h × 0.7 hours = 29.89 km

Now, let's calculate the new distance between the passenger train and the freight train.

3. Initial distance between the trains: 14.88 km 4. Distance traveled by the passenger train: 44.91 km 5. Distance traveled by the freight train: 29.89 km

To find the new distance between the trains, we subtract the sum of the distances traveled by the trains from the initial distance between them.

New distance = Initial distance - (Distance traveled by the passenger train + Distance traveled by the freight train) New distance = 14.88 km - (44.91 km + 29.89 km) New distance = 14.88 km - 74.8 km New distance = -59.92 km

The new distance between the passenger train and the freight train 0.7 hours ago was -59.92 km.

Please note that a negative distance indicates that the passenger train has overtaken the freight train.

Answer

The new distance between the passenger train and the freight train 0.7 hours ago was -59.92 km.