Question

Катер от пристани А до пристани В двигался со скоростью 80км/ч, а в обратную сторону со скоростью 120км/ч относительно берега. Найдите среднюю скорость движения катера на всем пути (туда и обратно)​

Answer 1

Ответ:

100 км\ч

Объяснение:

v =$\frac{80+120}{2}$=100 км\ч

Answer 2

Ответ:

Объяснение:

80км/ч + 120 км/ч= 200км/ч- разом

200:2= 100

Answer 3

Calculation of Average Speed

To find the average speed of the boat on the entire journey (both ways), we can use the formula:

Average Speed = Total Distance / Total Time

Let's calculate the average speed step by step.

1. Distance from Port A to Port B: - The boat travels from Port A to Port B with a speed of 80 km/h. - Let's assume the distance between Port A and Port B is d kilometers.

2. Distance from Port B to Port A: - The boat travels from Port B to Port A with a speed of 120 km/h. - The distance from Port B to Port A is also d kilometers.

3. Total Distance: - The total distance covered by the boat on the entire journey (both ways) is 2d kilometers.

4. Time taken from Port A to Port B: - The time taken to travel from Port A to Port B can be calculated using the formula Time = Distance / Speed. - The time taken from Port A to Port B is d / 80 hours.

5. Time taken from Port B to Port A: - The time taken to travel from Port B to Port A is d / 120 hours.

6. Total Time: - The total time taken for the entire journey (both ways) is (d / 80) + (d / 120) hours.

Now, let's calculate the average speed using the formula mentioned earlier:

Average Speed = Total Distance / Total Time

Average Speed = (2d) / [(d / 80) + (d / 120)]

Simplifying the expression:

Average Speed = (2d) / [(3d + 2d) / (240d)]

Average Speed = (2d) * (240d) / (3d + 2d)

Average Speed = (480d^2) / (5d)

Average Speed = 96d km/h

Therefore, the average speed of the boat on the entire journey (both ways) is 96d km/h.

Please note that the specific value of d (the distance between Port A and Port B) is not provided in the question, so we cannot determine the exact average speed.