Question

Два поезда выехали с одной станции в одном направлении.Первый поезд выехал на 2ч раньше другого и движется со скоростью 40км/ч, второй поезд - со скоростью 80км/ч. Через сколько часов второй поезд догонит первый? На каком расстоянии от станции отправления второй поезд догонит первый?Помогите очень надо!!!

Answer 1

1.) 40*2=80(км)-столько проехал первый поезд.

2.) 80x2=160(км) -на таком расстоянии он догонит.

3.) 160:80=2(ч) -через столько 2й поезд догонит первый.

Ответ: 2ч.

Answer 2

Problem Analysis

We have two trains that depart from the same station in the same direction. The first train departs 2 hours earlier than the second train and travels at a speed of 40 km/h, while the second train travels at a speed of 80 km/h. We need to determine how many hours it will take for the second train to catch up to the first train and at what distance from the departure station the second train will catch up.

Solution

Let's assume that the time it takes for the second train to catch up to the first train is t hours.

During this time, the first train will have traveled for t + 2 hours at a speed of 40 km/h, covering a distance of 40(t + 2) km.

The second train will have traveled for t hours at a speed of 80 km/h, covering a distance of 80t km.

To find the time it takes for the second train to catch up to the first train, we can set up the following equation:

40(t + 2) = 80t

Simplifying the equation:

40t + 80 = 80t

80 = 80t - 40t

80 = 40t

t = 2

Therefore, it will take the second train 2 hours to catch up to the first train.

To find the distance from the departure station where the second train catches up to the first train, we can substitute the value of t into either of the distance equations:

Distance covered by the second train = 80t = 80 * 2 = 160 km

Therefore, the second train will catch up to the first train at a distance of 160 km from the departure station.

Answer

The second train will catch up to the first train after 2 hours and at a distance of 160 km from the departure station.