Question

На первом участке пути поезда шел 2 ч со скоростью 60км/ч, а на втором он шел 3 ч . С какой скоростью шел поезд на втором участке , если его средняя скорость на двух участках была равна 51 км/ч

Answer 1

Сотавим уравнение , где Х это скорость поезда на втором участке;
(60*2 +Х*3):5=51
120+3х=51*5
120+3х=255
3х=255-120
3х=135
х=135:3
х=45 км/ч ( скорость поезда на втором участке).

Answer 2

Calculation of the Train's Speed on the Second Segment

To calculate the speed of the train on the second segment, we can use the formula for average speed:

Average Speed = Total Distance / Total Time

Let's denote the speed on the first segment as v1 (60 km/h) and the time spent on the first segment as t1 (2 hours). Similarly, let's denote the speed on the second segment as v2 (unknown) and the time spent on the second segment as t2 (3 hours). The average speed of the train on both segments is given as 51 km/h.

We can set up the following equation:

51 km/h = (Total Distance) / (Total Time)

The total distance is the sum of the distances on both segments, which can be calculated as:

Total Distance = Distance on First Segment + Distance on Second Segment

The distance on each segment can be calculated using the formula:

Distance = Speed x Time

Substituting the given values:

Total Distance = (v1 x t1) + (v2 x t2)

Now we can substitute the values into the equation for average speed:

51 km/h = [(v1 x t1) + (v2 x t2)] / (t1 + t2)

Simplifying the equation:

51 km/h = [(60 km/h x 2 hours) + (v2 x 3 hours)] / (2 hours + 3 hours)

51 km/h = (120 km + 3v2) / 5 hours

To find the value of v2, we can solve this equation for v2.

Let's solve the equation step by step:

1. Multiply both sides of the equation by 5 hours to eliminate the denominator:

5 hours x 51 km/h = 120 km + 3v2

2. Simplify:

255 km = 120 km + 3v2

3. Subtract 120 km from both sides:

255 km - 120 km = 3v2

4. Simplify:

135 km = 3v2

5. Divide both sides by 3:

45 km/h = v2

Therefore, the train's speed on the second segment was 45 km/h.

Please note that the calculation assumes a constant speed on each segment and does