Answer:
V=

Direction is normal to the incline
Step-by-step explanation:
This question tests on projectile motion.
First, calculate the acceleration of the missile.
Incline=55º,Distance=23500m, t=10seconds.
Horizontal motion of projectile

Final velocity

The vertical motion of the missile can be calculated as:

Final Velocity is:

Combining both we get

*Misile's motion is normal to the 55º incline.