# A boat moves through a river at 5.27 m/s relative to the water, regardless of the boat's direction.A boat moves through a river at 5.27 m/s relative to the water, regardless of the boat's...

A boat moves through a river at 5.27 m/s relative to the water, regardless of the boat's direction.

A boat moves through a river at 5.27 m/s relative to the water, regardless of the boat's direction.

If the water in the river is flowing at 1.78m/s, how long does it take the boat to make a round trip consisting of a 295m *displacement downstream *followed by a 295m *displacement upstream*? **Answer in units of seconds**

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### 1 Answer

The boat moves at a speed of 5.27 m/s relative to the water regardless of the boat's direction. The water is flowing at 1.78 m/s. When the boat moves downstream the speed of the boat is the sum of the speed of water and that of the boat. This is equal to 5.27+1.78 = 7.05 m/s. When the boat moves upstream the speed of the boat is the difference of the speed of the boat and that of the water. This is equal to 5.27 - 1.78 = 3.49 m/s.

The time take by the boat to travel 295 m downstream is 295/7.05 = 41.84 s and the time taken by the boat to travel 295 m upstream is 295/3.49 = 84.52 s

The total time taken by the boat to make a round trip 295 m downstream and 295 m upstream is 126.36 s.