A particle of mass `m` is projected from origin `O` with speed `u` at an angle `theta` with positive x-axis. Positive y-axis is in vertically upward. Direction. Find the angular momentum of particle at any time `t` about `O` before the particle strkes the ground again.

Explanation

To find the angular momentum of a particle of mass \( m \) projected from the origin \( O \) with speed \( u \) at an angle \( \theta \) with the positive x-axis, we can follow these steps:

### Step 1: Determine the Position of the Particle
The position of the particle at any time \( t \) can be expressed in terms of its horizontal and vertical components:
- The horizontal position \( x \) is given by:
\[ x = u \cos(\theta) t \]
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