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BARSIC [14]
4 years ago
9

A boat travels between two riverside cities, A and B, located 21 miles apart. The river flows in the direction from A to B at 2

mph. The boat takes a total of 10 hours to make a round trip from A to B and back to A again. How long does it take the boat to make the one-way trip from A to B if the boats speed remailer constant relative to the speed of the river in each direction
Physics
1 answer:
klasskru [66]4 years ago
4 0

Answer:

The time taken by the boat to make the one-way trip from A to B = 3 hrs

Explanation:

Distance between A & B = 21 mile

Velocity of river ( v ) = 2 \frac{mi}{hr}

Total time taken ( T )= 10 hours

T = \frac{D}{u - v}  + \frac{D}{u +v}

10 = \frac{21}{u - 2} +  \frac{21}{u + 2}

10 = \frac{42 u}{u^{2}-4 }

10 u^{2} - 42 u -40 = 0

u^{2} - 4.2 u - 4 = 0

By solving above equation we get

u = 5 \frac{mi}{hr}

The time taken by the boat to make the one-way trip from A to B

T = \frac{D}{u + v}

T = \frac{21}{5 + 2}

T = 3 hours

This is the time taken by the boat to make the one-way trip from A to B.

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Answer:

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Explanation:

given data ;

diameter of cylinder =  150 mm

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