Q. 84.6( 18 Votes )
A vertically straight tree, 15m height, is broken by the wind in such a way that its top just touches the ground and makes an angle of 60° with the ground. At what height from the ground did the tree break?
Total height of the tree is 15 m.
I.e AB= 15m.
Let height at which tree is broken is h (m)
Therefore BC = h (m)
CD = AB-BC
sin 60° =
√3(15-h) = 2h
⇒ 15√3-√3h = 2h
⇒ h(2+√3) = 15√3
on multiplying and dividing by 2-√3
h = ⇒ ⇒ 6.96 m.
Therefore the tree is broken at 6.96 m from the ground.
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