1.

A lotun flower is blooming in a lnke. The flower in metres above the surface ofthe lake. When the western wind blown, the flower droops at a distance of 2 mfrom the base. Pind the depth of the lake.

Answer»

The lotus flower is 1/2 m above the surface of the lake. Let us assume water has a depth y, then length of the stem will be (y + 1/2). The length of the stem is same. Now the distance of stem from original position(base) is 2 m

Taking water to be horizontal and stem to be straight(right angle(imagination),

using pythagoras theorem we have,

(y + 1/2)^2 = y^2 + 2^2

y^2 + 1/4 + 2. y. 1/2 = y^2 + 4

y^2 + 4 = y^2 + 1/4 + y

y = 4 - 1/4

y = 15 / 4

y = 3.7 m

Depth of lake is 3.7 m



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