Question

Собственная скорость теплохода равна 25,7 км\ч,а скорость течения реки 3,8км\ч.теплоход шел 3ч по озеру (вода в озере стоячая) и 3ч по течению реки.какое расстояние прошел теплоход за 6ч? успеет ли он пройти обратный путь за 7ч

Answer 1

25,7+3,8=29,5 скорость по течению
25,7-3,8=21,9км/ч скорость против течения
25,7*3=77,1км путь по озеру
29,5*3=88,5км путь по реке по течению
77,1+88,5=165,6 км весь путь
Обратный путь:
88,5/21,9~4 ч обратный путь по реке
И 3 часа по озеру

Answer 2

25,7*3+(25,7+3,8)*3=77,1+88,5=165,6
165,6-(25,7+25,7-3,8)*7=165,6-333,2
Ответ:не успеет

Answer 3

Calculation of Distance Traveled by the Boat

To calculate the distance traveled by the boat, we need to consider the time spent traveling on the lake and the time spent traveling against the river current.

The boat traveled at a speed of 25.7 km/h, and the river current had a speed of 3.8 km/h.

The boat traveled for 3 hours on the lake, where the water is still, and then for 3 hours against the river current.

To calculate the distance traveled on the lake, we can use the formula:

Distance = Speed × Time

Substituting the values, we get:

Distance on the lake = 25.7 km/h × 3 hours

To calculate the distance traveled against the river current, we need to consider the relative speed of the boat and the current. The relative speed is the difference between the boat's speed and the current's speed.

Relative Speed = Boat Speed - Current Speed

Substituting the values, we get:

Relative Speed = 25.7 km/h - 3.8 km/h

Now, we can calculate the distance traveled against the river current using the formula:

Distance = Relative Speed × Time

Substituting the values, we get:

Distance against the river current = (25.7 km/h - 3.8 km/h) × 3 hours

Finally, to calculate the total distance traveled by the boat in 6 hours, we add the distance on the lake and the distance against the river current:

Total Distance = Distance on the lake + Distance against the river current

Substituting the values, we get:

Total Distance = (25.7 km/h × 3 hours) + [(25.7 km/h - 3.8 km/h) × 3 hours]

Now, let's calculate the total distance traveled by the boat in 6 hours.

Calculation:

Distance on the lake = 25.7 km/h × 3 hours = 77.1 km Relative Speed = 25.7 km/h - 3.8 km/h = 21.9 km/h

Distance against the river current = 21.9 km/h × 3 hours = 65.7 km Total Distance = 77.1 km + 65.7 km = 142.8 km

Therefore, the boat traveled a total distance of 142.8 km in 6 hours.

Possibility of Completing the Return Journey in 7 Hours

To determine if the boat can complete the return journey in 7 hours, we need to consider the time spent traveling with the river current and the time spent traveling on the lake.

The boat traveled for 3 hours against the river current, so it will travel for 3 hours with the river current on the return journey.

To calculate the distance traveled with the river current, we can use the same formula as before:

Distance = Relative Speed × Time

Substituting the values, we get:

Distance with the river current = (25.7 km/h + 3.8 km/h) × 3 hours

Now, to calculate the total distance traveled on the return journey, we add the distance with the river current and the distance on the lake:

Total Distance on the return journey = Distance with the river current + Distance on the lake

Substituting the values, we get:

Total Distance on the return journey = [(25.7 km/h + 3.8 km/h) × 3 hours] + (25.7 km/h × 3 hours)

Now, let's calculate the total distance traveled on the return journey in 7 hours.

Calculation:

Distance with the river current = (25.7 km/h + 3.8 km/h) × 3 hours = 89.7 km Total Distance on the return journey = 89.7 km + 77.1 km = 166.8 km

Therefore, the boat will travel a total distance of 166.8 km on the return journey.

Since the boat traveled a total distance of 142.8 km in 6 hours and the total distance on the return journey is 166.8 km, it is clear that the boat will not be able to complete the return journey in 7 hours.