Question

Из двух городов,расстояние между которыми 30 км,одновременно в одном направлении вышли два поезда со скоростями 50 км/ч и70км/ч.Через сколько часов второй поезд догонит первый?

Answer 1

70-50=20км/ч на столько скоррость 2 больше

30:20=1,5 ч

ответ через 1,5ч

Answer 2

1)70-50= на 20км -скорость второго больше. 2)30:20=через 1,5ч(1ч 30мин) один поезд догонит другой.

Answer 3

Problem Analysis

We have two trains traveling in the same direction, with speeds of 50 km/h and 70 km/h, respectively. We need to determine how many hours it will take for the second train to catch up to the first train, given that the distance between the two cities is 30 km.

Solution

To solve this problem, we can use the formula:

time = distance / relative speed

The relative speed is the difference between the speeds of the two trains. Let's calculate the time it will take for the second train to catch up to the first train.

Calculation

The relative speed of the second train with respect to the first train is 70 km/h - 50 km/h = 20 km/h.

Using the formula, we can calculate the time it will take for the second train to catch up to the first train:

time = distance / relative speed

Substituting the values, we get:

time = 30 km / 20 km/h

Simplifying, we find:

time = 1.5 hours

Therefore, the second train will catch up to the first train in 1.5 hours.

Answer

The second train will catch up to the first train in 1.5 hours.