During a rainy day, rain is falling vertically with a velocity `2m//s` A boy at rest starts his motion with a constant acceleration of `2m//s^(2)` along a straight road . Find the rate at which the angle of the axis of umbrella with vertical should be changed so that the rain always falls parallel to the axis of the umbrella.

Explanation

To solve the problem step by step, we will analyze the motion of the boy and the rain, and find the angle at which the umbrella should be tilted.

### Step 1: Understand the velocities involved
- The rain is falling vertically downwards with a velocity \( V_r = 2 \, \text{m/s} \).
- The boy is at rest initially and starts moving with a constant acceleration \( a = 2 \, \text{m/s}^2 \).

### Step 2: Calculate the boy's velocity
- The boy's velocity \( V_b \) at any time \( t \) can be calculated using the first equation of motion:
...