Question

От двух станций, расстояние между которыми 56км, отошли одновременно в противоположных направлениях два поезда. Средняя скорость одного поезда 45км/ч, средняя скорость другого-на 12км/ч больше. Какое расстояние будет между этими поездами через 3ч.? через 10ч.?

Answer 1

45 х 3 = 135 км пройдёт 1-ый поезд за 3 часа;

45+ 12= 57 км\ч - скорость 2-ого

57 х 3 = 171км пройдёт 2-ой поезд за 3 часа

135 + 171 + 56 = 362 км будет между поездами через 3 часа.

 второе условие: 45х10 = 450 км

                                57 х 10 = 570 км

                                450 + 570 + 56 = 1076 км будет между поездами через 10 часов

Answer 2

Problem Analysis

We have two trains that start simultaneously from two stations that are 56 km apart. The first train has an average speed of 45 km/h, while the second train has an average speed that is 12 km/h faster than the first train. We need to find the distance between the two trains after 3 hours and after 10 hours.

Solution

To find the distance between the two trains after a certain time, we need to calculate the total distance traveled by each train and then find the difference between the two distances.

Let's calculate the distance traveled by each train after 3 hours and after 10 hours.

Calculation

1. Distance traveled by the first train after 3 hours: - Speed of the first train = 45 km/h - Time = 3 hours - Distance = Speed * Time = 45 km/h * 3 hours = 135 km

2. Distance traveled by the second train after 3 hours: - Speed of the second train = 45 km/h + 12 km/h = 57 km/h (12 km/h faster than the first train) - Time = 3 hours - Distance = Speed * Time = 57 km/h * 3 hours = 171 km

3. Distance between the two trains after 3 hours: - Distance between the two trains = Distance traveled by the second train - Distance traveled by the first train = 171 km - 135 km = 36 km

4. Distance traveled by the first train after 10 hours: - Speed of the first train = 45 km/h - Time = 10 hours - Distance = Speed * Time = 45 km/h * 10 hours = 450 km

5. Distance traveled by the second train after 10 hours: - Speed of the second train = 45 km/h + 12 km/h = 57 km/h (12 km/h faster than the first train) - Time = 10 hours - Distance = Speed * Time = 57 km/h * 10 hours = 570 km

6. Distance between the two trains after 10 hours: - Distance between the two trains = Distance traveled by the second train - Distance traveled by the first train = 570 km - 450 km = 120 km

Answer

The distance between the two trains after 3 hours is 36 km, and after 10 hours is 120 km.

Please let me know if you need any further clarification.