Question

Ррасстояние между пристанями по реке 12 км . Моторная лодка проплыла от одной пристани до другой и вернулась обратно . Сколько часов потратила лодка на весь путь , если скорость лодки 6 км/ч , скорость течения реки 2 км/ч?

Answer 1

Vпо теч=Vсобств+Vтеч

Vпрот.теч=Vсобств-Vтеч

t=s:v

 

12:(6+2)  + 12:(6-2) =1,5+3=4,5(час).

 

1) 6+2=8(км/ч) - скорость по течению

2) 6-2=4(км/ч) - скорость против течения

3) 12:8=1 1/2(час) - время в пути по течению

4) 12:4=3(час) - время в пути против течения

5) 1,5+3=4,5(час) - всего была лодка в пути

Answer 2

Calculating the Time Taken for the Boat Journey

To calculate the time taken for the boat journey, we can use the formula: time = distance / (boat speed + river current speed).

Given: - Distance between the piers: 12 km - Boat speed: 6 km/h - River current speed: 2 km/h

Using the formula, we can calculate the time taken for the boat to travel from one pier to the other and back.

Calculating the Time for One Leg of the Journey

The time taken for the boat to travel from one pier to the other can be calculated using the formula: time = distance / (boat speed + river current speed).

Substituting the given values: time = 12 km / (6 km/h + 2 km/h) time = 12 km / 8 km/h time = 1.5 hours

Total Time for the Entire Journey

Since the boat has to travel from one pier to the other and then back, the total time for the entire journey can be calculated by doubling the time for one leg of the journey.

Doubling the time for one leg of the journey: total time = 1.5 hours * 2 total time = 3 hours

Therefore, the boat spent 3 hours for the entire journey.