Answer:
Velocity of the fish relative to the water when it hits the water = 14.32 m/s along 77.91° below horizontal.
Step-by-step explanation:
Vertical motion of fish:
Initial speed, u = 0
Acceleration, a = 9.81 m/s²
Displacement, s = 10 m
We have equation of motion, v² = u² + 2as
Substituting
v² = 0² + 2 x 9.81 x 10 = 196.2
v = 14 m/s
Final vertical speed = 14 m/s
Final horizontal speed = initial horizontal speed = 3 m/s
Final velocity = 3 i - 14 j m/s
Magnitude

Direction

Velocity of the fish relative to the water when it hits the water = 14.32 m/s along 77.91° below horizontal.