A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O the ground is '45°' It 'flies' off horizontally straight a Way from 1 the point O. After one second, the elevation of,the bird from O is reduced to 30°. Then the 'speed' (m m/s) of the bird is

Question

A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O the ground is '45°' It 'flies' off horizontally straight a Way from 1 the point O. After one second, the elevation of,the bird from O is reduced to 30°. Then the 'speed' (m m/s) of the bird is (A) 20 √ 2 (B) 20 (√ 3-1) (C) 40 (√ 2-1) (D) 40 (√ 3 -√ 2)

Tardigrade Admin · Accepted Answer

Correct answer is (b) 20 (√ 3-1)

$202$

$20 (3 - 1)$

$40 (2 - 1)$

$40 (3 - 2)$

Correct answer is (b) $20 (3 - 1)$

Q. A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O the ground is '45∘' It 'flies' off horizontally straight a Way from 1 the point O. After one second, the elevation of,the bird from O is reduced to 30∘. Then the 'speed' (m m/s) of the bird is

202​

20(3​−1)

40(2​−1)

40(3​−2​)

Correct answer is (b) 20(3​−1)

$202$

$20 (3 - 1)$

$40 (2 - 1)$

$40 (3 - 2)$

Correct answer is (b) $20 (3 - 1)$