A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O on the ground is `45o` . It flies off horizontally straight away from the point O. After one second, the elevation of the bird from O is reduced to `30o` . Then the speed (in m/s) of the bird is (1) `40(sqrt(2)-1)` (2) `40(sqrt(3)-2)` (3) `20""sqrt(2)` (4) `20(sqrt(3)-1)`

A snake observes an eagle perching on the top of a pole 20 m high. Its elevation from snake s eye is 45^@ before it hies off horizontally straight away from the snake and after one second the elevation of the eagle reduces to 30^@ .The speed of the eagle is

A bird is sitting on the top of a 80 m high tree. From a point on the ground, the angle of elevation of the bird is 45. The bird flies away horizontally in such a way that it remained at a constant height from the ground. After 2sec the angle of elevation of the bird from the same point is 30. Find the speed of flying of the bird.

A bird is sitting on the top of an 80 m high tree. From a point on the ground, the angle of elevation of the bird is 45^(@) . The bird flies away horizontally in such a way that it remained at a constant height from the ground. After 2 seconds, the angle of elevation of the bird from the same point is 30^(@) . Find the speed of flying of the bird. (Take sqrt3=1.732 ).

A bird is sitting on the top of a 80 m high tree. From a point on the ground, the angle of elevation of the bird is theta is 45. The flies away horizontaly in such a way that it remained at a constant height from the ground.After 2 sec the angle of elevation of bird from the same point is theta is 30.Find the speed of flying of the bird.

If the angle of elevation of top of a tower from a point on the ground which is 20sqrt(3) m away from the foot of the tower is 30^(@) , then find the height of the tower.

If the angle of elevation of a tower from a distance of 100 metres from its foot is 60o , then the height of the tower is 100sqrt(3)m (b) (100)/(sqrt(3))m( c) 50sqrt(3)( d) (200)/(sqrt(3))m

The angle of elevation of the top of a tower from a point on the ground,which is 30m away from the foot of the tower is 30o. Find the height of the tower.

The angle of elevation of an aeroplane from a point on the ground is 45o .After a flight of 15 seconds,the elevation changes to 30o .If the aeroplane is flying at a height of 3000 metres, find the speed of the aeroplane.

AB is a vertical pole with B at the ground level and A at the top. A man finds that the angle of elevation of the point A from a certain point C on the ground is 60o . He moves away from the pole along the line BC to a point D such that C D""=""7""m . From D the angle of elevation of the point A is 45o . Then the height of the pole is (1) (7sqrt(3))/2dot1/(sqrt(3)-1)m (2) (7sqrt(3))/2dot(sqrt(3)+1)m (3) (7sqrt(3))/2dot(sqrt(3)-1)m (4) (7sqrt(3))/2dot1/(sqrt(3)+1)m