2016 · Q73
A man from the top of a 100 m high tower sees a car moving towards the tower at an angle of depression 30°. After some time, the angle of depression becomes 60°. What is the distance travelled by the car during this time ?
Elementary MathematicsTrigonometry
- A1003 m
- B{2003}3 m
- C{1003}3 m
- D2003 m
Explanation
Distances of the two positions from the tower foot: 100/tan30° = 100√3 and 100/tan60° = 100/√3. The car travels 100√3−100/√3 = 200/√3 = 200√3/3 m. That is option B (rendered '200√3/3').