A projectile is fired with a speed `u` at an angle `theta` with the horizontal. Find its speed when its direcrtion of motion makes an angle `alpha` with the horizontal.

Explanation

To solve the problem of finding the speed of a projectile when its direction of motion makes an angle \( \alpha \) with the horizontal, we can follow these steps:

### Step 1: Understand the Components of Motion
In projectile motion, the motion can be analyzed in two dimensions: horizontal (x-direction) and vertical (y-direction). The initial velocity \( u \) can be broken down into its components:
- Horizontal component: \( u_x = u \cos \theta \)
- Vertical component: \( u_y = u \sin \theta \)

### Step 2: Analyze the Horizontal Motion
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