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 α with the horizontal, we can follow these steps:

### Step 1: Understand the Initial Conditions
The projectile is fired with an initial speed \( u \) at an angle \( \theta \) with the horizontal. The initial horizontal and vertical components of the velocity can be expressed as:
- Horizontal component: \( u_x = u \cos \theta \)
- Vertical component: \( u_y = u \sin \theta \)

### Step 2: Analyze the Horizontal Motion
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