Question

2. Лодка проплыла 60 км вниз по течению и обратно 20 км вверх по течению. Скорость потока 1 км/ч. На всю поездку уйдет 7 часов. Найдите скорость лодки. [6]​

Answer 1

Ответ:воть по поводу ответа не очень уверен

Объяснение:

Answer 2

Calculation of Boat Speed

To find the speed of the boat, we can use the formula:

Speed = Distance / Time

Let's break down the given information:

- The boat traveled 60 km downstream (in the direction of the current) and then returned 20 km upstream (against the current). - The speed of the current is 1 km/h. - The total time for the trip is 7 hours.

To calculate the speed of the boat, we need to determine the time it took for the boat to travel downstream and upstream.

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

Calculation of Time Downstream

When the boat is traveling downstream, the effective speed is the sum of the boat's speed and the speed of the current. Therefore, the time taken to travel downstream can be calculated as:

Time Downstream = Distance Downstream / (Boat Speed + Current Speed)

Substituting the given values:

Time Downstream = 60 km / (x km/h + 1 km/h)

Calculation of Time Upstream

When the boat is traveling upstream, the effective speed is the difference between the boat's speed and the speed of the current. Therefore, the time taken to travel upstream can be calculated as:

Time Upstream = Distance Upstream / (Boat Speed - Current Speed)

Substituting the given values:

Time Upstream = 20 km / (x km/h - 1 km/h)

Total Time for the Trip

The total time for the trip is given as 7 hours. Therefore, the sum of the time taken downstream and the time taken upstream should be equal to 7 hours:

Time Downstream + Time Upstream = 7 hours

Solving the Equations

We can now solve the equations to find the value of x, which represents the speed of the boat.

1. From the equation for time downstream: Time Downstream = 60 km / (x km/h + 1 km/h)

2. From the equation for time upstream: Time Upstream = 20 km / (x km/h - 1 km/h)

3. From the equation for total time: Time Downstream + Time Upstream = 7 hours

By substituting the values and solving the equations, we can find the speed of the boat.