Find the average velocilty of a projectile between the instants it crosses half the maximum height. It is projected with speed u ast angle `theta` with the horizontal.

Explanation

To find the average velocity of a projectile between the instants it crosses half the maximum height, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Motion of the Projectile:**
- A projectile is launched with an initial speed \( u \) at an angle \( \theta \) to the horizontal. The motion can be separated into horizontal and vertical components.

2. **Determine the Maximum Height:**
...