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It takes a boat going upstream 11 hours to cover the same distance, as it would cover in 9 hours going downstream. What is the speed of the boat if the speed of the current is 2 km/hr?

Respuesta :

Answer:

20 km/hr

Explanation:

time taken by the boat going upstream = 11 hours

time taken for downstream movement = 9 hours

speed of the current = 2 km/h

distance traveled by the boat = d

Assume the speed of boat be x

we know,

distance =  speed × time

moving upstream

distance = speed × time

            d  = (x -2) × 11

downstream

             d = (x+2) × 9

now  

       (x+2) × 9 = (x -2) × 11

              2 x = 40

                 x = 20 km/hr

hence, the speed of the boat will be 20 km/hr

annyksl

The speed of the boat would be equal to 20 km/h.

How can we arrive at this result?

  • We will use the formula to calculate the distance traveled by a body. This formula presents the equation:

[tex]\Delta D=\Delta S*\Delta T[/tex]

  • In this equation [tex]\Delta D[/tex] is the distance traveled, while [tex]\Delta S[/tex] is the speed and [tex]\Delta T[/tex] is the time taken by the vehicle.

  • As we do not know the speed used by the boat either to go up or down, we will consider that when going up the speed was equal to x-2, while when going down the speed was equal to x+2, considering the speed of the current.

  • In this case, we'll use the two distance traveled equations, and form a single equation. This equation will be:

[tex]\Delta S_1*\Delta T_1=\Delta S_2*\DElta T_2\\(x+2) * 9 = (x -2) * 11\\2 x = 40\\x= \frac{40}{2} \\x=20 km/h[/tex]

More information about speed is in the link:

https://brainly.com/question/4931057

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