question_answer

The distance of fly at the end of the string from the point over the water surface just below the tip of fishing rod, after 12 seconds is:

A) \[\text{1}.\text{2 m}\]

B) \[\text{2}.\text{52 m}\]

C) \[\text{1}.\text{59 m}\]

D) \[\text{2}.\text{79 m}\]

Correct Answer: C

Solution :

\[B{{D}^{2}}=A{{D}^{2}}-A{{B}^{2}}\] (By Pythagoras theorem)

\[={{(2.4)}^{2}}-{{(1.8)}^{2}}=5.76-3.24=2.52\]

\[\Rightarrow \,\,\,\,BD=\sqrt{2.52}=1.59m\] (Approx.)

So, option [c] is correct.