Answer:
v = 14.13 m/s
Step-by-step explanation:
We are given;
Height of platform above water; S_y = 10.1m
Horizontal component of velocity; V_x = 1.28 m/s
First of all, let's find time taken for the displacement.
t = √[(2S_y)/g]
t = √[(2 x 10.1)/9.8]
t = √[(20.2)/9.8]
t = 1.436 s
Let's use Newton's equation of motion for vertical component of velocity;
(v_y) = u + gt
(v_y) = 0 + (9. 8 x 1.436)
(v_y) = 14.07 m/s
So, final speed is the resultant of v_x and v_y.
So;
v = √((v_x)² + (v_y)²)
v = √((1.28)² + (14.07)²)
v = √199.6033
v = 14.13 m/s