The angle of elevation of a jet plane from a point A on the ground is `60^@`. After a flight of 15 secondsthe angle of elevation changes to `30^@`. If the jet plane is flying at a constant height of `1500sqrt3m`, find the speed of the jet plane.

The angle of elevation of the top Q of a vertical tower PQ from a point X on the ground is 60^@ . At a point Y, 40 m vertically above X, the angle of elevation is 45^@ . Find the height of the tower PQ and the distance XQ.

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

The angle of elevation of the top of a tower from a point O, on the ground, which is 600 m away from the foot of the tower, is 45^@ . Obtain the height of the tower.

The angle of elevation of the top of a tower from a point A on the ground is 30^@ . On moving a distance of 20 metres towards the foot of the tower to a point B, the angle of elevation increases to 60^@ . Find the height of the tower and distance of the tower from the point A.

The angle of elevation of a cloud from a point 200 m above the lake is 30^@ and the angle of depression of the reflection of the cloud in the lake is 60^@ . Find the height of the cloud.

The angle of elevation of the top of a building from the foot of the tower is 30^@ and the angle of elevation of the top of the tower from the foot of the building is 60^@ . If the tower is 50 m high, find the height of the building.

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 60^@ . He moves away from the pole along the line BC to a point D such that CD =7m. From D, the angle of elevation of the point A is 45^@ . Then the length of the pole is:

From the top of a building 15 m high, the angle of elevation of the top of a tower is found to be 30^@ . From the bottom of the same building, the angle of elevation of the top of the tower is found to be 60°. Find the height of the tower and the distance between the tower and the building.

A TV tower stands vertically on a bank of a canal. From a point on the other bank directly opposite the tower, the angle of elevation of the top of the tower is 60^@ . From a point 20maway from this point on the same bank, the angle of elevation of the top of the tower is 30^@ (see fig.). Find the height of the tower and the width of the canal.

A pole 5 m high is fixed on the top of a tower. The angle of elevation of the top of the pole observed from a point 'A' on the ground is 60^@ and the angle of depression of the point ‘A’ from the top of the tower is 45^@ . Find the height of the tower