A boat moves with full power downstream in a river. At t = 0 it was right infront of a point A on the shore. At t = 1 hr it was right infront of a point B where it turns back and starts moving upstrea

Question

A boat moves with full power downstream in a river. At $t = 0$ it was right infront of a point A on the shore. At $t = 1 hr$ it was right infront of a point B where it turns back and starts moving upstream with full power. A plank that is floating in river was met at $t = 0$ by the boat and was again met at C while going upstream. If $AB = 6 km$ and $AC = 4 km$ , the value of t when boat returns back infront of A is :-

Options:

Answer:

C

Solution:

$t_{AB} = t_{BC} = 1 hr$

∵ in upstream

$CA = 2 BC$

$t_{CA} = 2 t_{BC} = 2 hr$

total time $t_{AB} + t_{BC} + t_{CA} = 1 + 1 + 2 = 4 hr$

TestHub · Accepted Answer

t AB ​ = t BC ​ = 1 hr ∵ in upstream CA = 2 BC t CA ​ = 2 t BC ​ = 2 hr total time t AB ​ + t BC ​ + t CA ​ = 1 + 1 + 2 = 4 hr

Physics - Kinematics Question with Solution | TestHub

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