Mathematics
A man on the top of a vertical observation tower observes a car moving at a uniform speed coming directly towards it. If it takes 10 minutes for the angle of depression to change from 30° to 45°, how soon after this will the car reach the observation tower? Give your answer to the nearest second.
Related Questions
In the given figure, AB represents a pole and CD represents a 60 m high tower, both of which are standing on the same horizontal plane. From the top of the tower, the angles of depression of the top and the foot of the pole are 30° and 60° respectively. Calculate:
(i) the horizontal distance between the pole and the tower,
(ii) the height of the pole.
From a boat, 200 m away from a vertical cliff, the angles of elevation of the top and the foot of a vertical pillar at the edge of the cliff are 36° and 34° respectively. Find:
(i) the height of the cliff, and
(ii) the height of the pillar.
The angle of elevation of a stationary cloud from a point 25 m above a lake is 30° and the angle of depression of its reflection in the lake is 60°. What is the height of the cloud above the lake-level?
A tower subtends an angle α on the same level as the foot of the tower and at a second point h metres above the first, the depression of the foot of the tower is β. Show that the height of the tower is h tan α cot β.