Question

Теплоход прошел 74,58км по течению реки и 131,85км против течения. Сколько времени теплоход был в пути, если его собственная скорость 31,6км/ч, а скорость течения- 2,3км/ч

Answer 1

31.6+2.3=33.9 (км/ч)

74.58:33.9=2.2 ( ч )

31.6-2.3=29.3 (км/ч)

131.85:29.3=4.5 ( ч )

Answer 2

Calculation of Time Taken by the Boat

To calculate the time taken by the boat, we need to consider the distances traveled both with and against the current of the river.

Given: - Distance traveled with the current = 74.58 km - Distance traveled against the current = 131.85 km - Boat's own speed = 31.6 km/h - Speed of the current = 2.3 km/h

To calculate the time taken with the current, we divide the distance by the effective speed of the boat, which is the sum of the boat's own speed and the speed of the current: Time taken with the current = Distance / (Boat's speed + Current's speed)

To calculate the time taken against the current, we divide the distance by the effective speed of the boat, which is the difference between the boat's own speed and the speed of the current: Time taken against the current = Distance / (Boat's speed - Current's speed)

Let's calculate the time taken with and against the current.

Time taken with the current: Distance = 74.58 km Boat's speed = 31.6 km/h Current's speed = 2.3 km/h

Time taken with the current = 74.58 km / (31.6 km/h + 2.3 km/h) = 74.58 km / 33.9 km/h

Time taken against the current: Distance = 131.85 km Boat's speed = 31.6 km/h Current's speed = 2.3 km/h

Time taken against the current = 131.85 km / (31.6 km/h - 2.3 km/h) = 131.85 km / 29.3 km/h

Now, let's calculate the actual time taken by adding the time taken with the current and the time taken against the current.

Total time taken: Total time taken = Time taken with the current + Time taken against the current

Now, let's calculate the values.

Time taken with the current = 74.58 km / 33.9 km/h = 2.2 hours Time taken against the current = 131.85 km / 29.3 km/h = 4.5 hours

Total time taken = 2.2 hours + 4.5 hours = 6.7 hours

Therefore, the boat was in motion for approximately 6.7 hours.