A straight highway leads to the foot of a tower. A man standing at the...
Given Information:
- The angle of depression of the car from the top of the tower is 30° initially.
- Six seconds later, the angle of depression of the car is 60°.
- The car is approaching the foot of the tower with a uniform speed.
Approach:
1. We can use trigonometry to solve this problem.
2. Let's assume the height of the tower is 'h' and the distance of the car from the foot of the tower at the initial observation is 'x'.
3. Using the angle of depression of 30°, we can write the equation: tan(30°) = h/x.
4. After 6 seconds, the car is closer to the tower, and the angle of depression is 60°. Let's assume the distance covered by the car in these 6 seconds is 'd'.
5. Using the angle of depression of 60°, we can write the equation: tan(60°) = h/(x-d).
Solving the Equations:
1. From the first equation, we get: x = h/tan(30°).
2. Substituting this value of x in the second equation, we get: tan(60°) = h/(h/tan(30°)-d).
3. Simplifying further, we get: √3 = tan(30°)/(1 - (d/h*tan(30°))).
4. Rearranging the equation, we get: √3 - √3(d/h*tan(30°)) = tan(30°).
5. Dividing both sides of the equation by √3, we get: 1 - d/h*tan(30°) = 1/√3.
6. Rearranging again, we get: d/h*tan(30°) = 1 - 1/√3.
7. Simplifying, we get: d/h = (√3 - 1)/(√3*tan(30°)).
8. Using the values of √3 and tan(30°), we get: d/h = (√3 - 1)/(√3*(1/√3)).
9. Simplifying further, we get: d/h = (√3 - 1).
Conclusion:
- The ratio of the distance covered by the car in 6 seconds to the height of the tower is (√3 - 1).
- This means the car covers a distance (√3 - 1) times the height of the tower in 6 seconds.
- Therefore, the time taken by the car to reach the foot of the tower from the point of observation is 6 seconds.