question_answer

One flies a kite with a thread 150 m long. If the thread of the kite makes an angle of \[60{}^\circ \] with the horizontal line, then the height of the kite from the ground (assuming the thread to be in a straight line) is

A) \[50\,m\]

B) \[75\sqrt{3}\,m\]

C) \[25\sqrt{3}\,m\]

D) \[80\,m\]

Correct Answer: B

Solution :

[b] Suppose the height of the kite from the ground \[=h\,m\]             \[\therefore \]      \[\sin 60{}^\circ =\frac{AB}{150}\]             \[\Rightarrow \]   \[\frac{\sqrt{3}}{2}=\frac{AB}{150}\]\[\Rightarrow \]\[\frac{\sqrt{3}}{2}=\frac{h}{150}\]             \[\Rightarrow \]   \[h=75\sqrt{3}\,m\]