Question

A man travels from point A to point B, which is at a higher elevation by boat and returns back in 27 hours. If the speed of boat in still water is 15 m/sec and speed of the current is 34 km/ hr then the distance between A and B is

Answer 1

Given:
Speed of boat in still water = 15m/s=54km/h
Speed of the current = 34km/h
Now,
Let the distance between A and B be 'x'
Let the time taken by boat to go upstream be 'T' and that to come downstream be 't'.
According to the question,
T + t = 27
Using concept of relativity:
$\frac{x}{(54 - 34)} + \frac{x}{(54 + 34)} = 27 \\ \frac{x}{20} + \frac{x}{88} = 27 \\ \frac{88x + 20x}{1760} = 27 \\ \frac{108x}{1760} = 27 \\ \frac{x}{440} = 1 \\ x = 440km \: (ans)$

Answer 2

Answer:

Distance between point A and B is 440 km.

Explanation:

What is Speed in Upstream and Downstream ?

A stream is a section of river that has flowing water in it.

Upstream refers to the direction in which the boat is moving relative to the stream. The term "upstream speed" is used to describe the boat's net speed in this instance.

A boat is said to be moving downstream if it is moving in the stream's direction. Here, the term "downstream speed" refers to the boat's net speed.

Still Water is regarded to be stagnant and moving at a speed of zero in this situation.

Speed of boat in still water = 15 m/sec = $15 * \frac{18}{5} = 54$ km /hr

Speed of current = 34 km/ hr

Time taken to travel upstream be x hr.

Time taken to travel downstream is 27- x hr.

Therefore,

(54-34)x = (54 + 34)(27-x)

⇒ 20x = 2376 -88x

⇒ 108x = 2376

⇒ x = 22

Distance between point A and B is = (54-34) * 22 = 20 *22 = 440 km

To learn more about Upstream and Downstream refer to :

https://brainly.in/question/14290035?referrer=searchResults

https://brainly.in/question/10473508?referrer=searchResults

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