Answer:
-3802 m/s
Explanation:
The y-component of the final velocity is ...
(6598 m/s)·sin(-20.5°) ≈ -2310.7 m/s
The y-component of the velocity due to acceleration is ...
(5200 m/s²)(0.350 s)sin(55°) ≈ 1490.9 m/s
Then the initial velocity in the y-direction is found from ...
initial velocity + change in velocity = final velocity
initial velocity = (final velocity) - (change in velocity)
= -2310.7 m/s - 1490.9 m/s ≈ -3802 m/s
