A straight highway leads to the foot of a tower. A man standing at the top of the tower observes a car at an angle of depression of `30^@`, which is approaching the foot of the tower with a uniform speed. Six seconds later, the angle of depression of the car is found to be `60^@`. Find the time taken by the car to reach the foot of the tower from this point.

Explanation

To solve the problem, we will use the properties of right triangles and trigonometric ratios. Let's break down the solution step by step.

### Step 1: Define the problem
Let the height of the tower be \( H \). The car is initially at point \( C \) when the angle of depression from the top of the tower (point \( P \)) is \( 30^\circ \). After 6 seconds, the angle of depression changes to \( 60^\circ \) when the car reaches point \( B \).

### Step 2: Set up the triangles
From the top of the tower, we can form two right triangles:
1. Triangle \( PCQ \) (where \( C \) is the initial position of the car).
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