Question

Помогите, пожалуйста, с задачей: Из железнодорожных вокзалов двух городов, расстояние между которыми 980км, навстречу друг к другу одновременно выехали два электропоезда и встретились через 7 часов. Найдите скорость второго поезда, если скорость первого поезда 68 км.ч

Answer 1

Выражение: 980 : 7 - 68 = 72.

1) 980 : 7 = 140 (км/ч) - скорость сближения;

2) 140 - 68 = 72 (км/ч) - скорость второго поезда.

Ответ: 72 км/ч.

Answer 2

Ответ:

68*7=476(км)-скорость1 поезда

980-476=504(км)

504:7=72(км/ч)-скорость 2 поезда

ответ:72км/ч

Answer 3

Problem Analysis

We are given that two electric trains start simultaneously from two railway stations and meet each other after 7 hours. The distance between the two stations is 980 km. We need to find the speed of the second train, given that the speed of the first train is 68 km/h.

Solution

Let's assume the speed of the second train is x km/h.

We can use the formula distance = speed × time to solve this problem.

The first train travels for 7 hours at a speed of 68 km/h, so the distance it covers is: distance = speed × time = 68 km/h × 7 hours = 476 km.

Since the two trains meet each other, the sum of the distances covered by both trains should be equal to the total distance between the two stations, which is 980 km.

So, the distance covered by the second train is: distance = total distance - distance covered by the first train = 980 km - 476 km = 504 km.

Now, we can use the formula distance = speed × time for the second train: 504 km = x km/h × 7 hours.

To find the value of x, we can rearrange the equation: x km/h = 504 km / 7 hours.

Simplifying the equation, we get: x km/h = 72 km/h.

Therefore, the speed of the second train is 72 km/h.

Answer

The speed of the second train is 72 km/h.

Verification

Let's verify the answer using the given information.

The first train travels at a speed of 68 km/h for 7 hours, covering a distance of 476 km.

The second train travels at a speed of 72 km/h for 7 hours, covering a distance of 504 km.

The sum of the distances covered by both trains is 476 km + 504 km = 980 km, which is equal to the total distance between the two stations.

Therefore, the answer is verified.