Multiple choice

Set the drifts suffered by boat in decreasing order. a) $d = 1000 m$ ; V${r}$= 2 ms$^{-1}$ ; V${b}$= 4 ms$^{-1}$ b) $d = 500 m$ ; V${r}$= 1 ms$^{-1}$ ; V${b}$= 6 ms$^{-1}$ c) $d = 1000 m$ ; V${r}$= 6 ms$^{-1}$ ; V${b}$= 6 ms$^{-1}$ [Here $d =$ width of river, V${r}$= Velocity of water in river ; V${b}$= Velocity of boat in still water]

  1. $a, b, c$
  2. $b, c, a$
  3. $c, a, b$
  4. $c, b, a$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Drift = (Vr / Vb) * d. a) (2/4) * 1000 = 500. b) (1/6) * 500 = 83.3. c) (6/6) * 1000 = 1000. Decreasing order: c (1000), a (500), b (83.3).

AI explanation

The drift of a boat crossing a river is given by the formula x equals the width of the river multiplied by the river velocity, divided by the perpendicular component of the boat's velocity. For case a, the drift is 1000 times 2 divided by 4, which equals 500 meters; for case b, the drift is 500 times 1 divided by 6, which equals 83.33 meters; and for case c, the drift is 1000 times 6 divided by 6, which equals 1000 meters. Comparing these calculated values, the decreasing order of the drifts is 1000 meters, 500 meters, and 83.33 meters, corresponding to the sequence c, a, b.

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