Question

Помогите пожалуйста! Скорость течения реки 5 км/ч. Теплоход проплыл по течению 240 км за 8 ч.Какое время необходимо затратить ему на обратный путь,если собственная скорость теплохода не изменилась?

Answer 1

240÷8=30 км/ч скорость теплохода по течению
30-5=25 км/ч скорость теплохода
25-5=20 км/ч скорость теплохода против течения
240/20=12 ч необходимо затратить теплоходе на обратный путь

Answer 2

Calculation of Time for the Return Journey

To calculate the time required for the return journey of the ship, we can use the concept of relative velocity. The relative velocity is the difference between the velocity of the ship and the velocity of the river current.

Given: - Velocity of the river current: 5 km/h - Distance covered by the ship with the current: 240 km - Time taken for the journey with the current: 8 hours

To find the time required for the return journey, we need to calculate the distance covered by the ship against the current.

Let's assume the time required for the return journey is t hours.

The distance covered by the ship against the current can be calculated using the formula:

Distance = Velocity × Time

For the journey with the current: Distance = (Velocity of the ship + Velocity of the current) × Time

For the return journey against the current: Distance = (Velocity of the ship - Velocity of the current) × t

Since the velocity of the ship remains unchanged, we can equate the distances for both journeys:

(Velocity of the ship + Velocity of the current) × Time = (Velocity of the ship - Velocity of the current) × t

Simplifying the equation:

(Velocity of the ship + 5) × 8 = (Velocity of the ship - 5) × t

Now, we can solve this equation to find the value of t.

Let's calculate it:

(Velocity of the ship + 5) × 8 = (Velocity of the ship - 5) × t

(8V + 40) = (V - 5) × t

8V + 40 = Vt - 5t

8V - Vt = -5t - 40

V(8 - t) = -5t - 40

V = (-5t - 40) / (8 - t)

Since we don't have the value of the ship's velocity (V), we cannot calculate the exact time required for the return journey without this information.

Please provide the velocity of the ship, and I will be able to calculate the time required for the return journey.