This is a projectile motion problem. We need to find the time of flight, the horizontal range, and the final velocity.

This is a projectile motion problem. We need to find the time of flight, the horizontal range, and the final velocity.

Given:
Initial horizontal velocity, $u_x = 50 \text{ m/s}$
Initial vertical velocity, $u_y = 0 \text{ m/s}$ (since it's fired horizontally)
Height of the cliff, $h = 90 \text{ m}$
Acceleration due to gravity, $g = 10 \text{ m/s}^2$

Step 1: Calculate the time to strike the ground ($t$)
We use the vertical motion equation:

$$h = u_y t + \frac{1}{2} g t^2$$

Since $u_