Answer:
v = 2,425 m / s
Explanation:
A simple pendulum has anergy stored at the highest point of the path and this energy is conserved throughout the movement.
highest point
Em₀ = U = m g y
lowest point
= K = ½ m v²
Em₀ = Em_{f}
mg y = ½ m v²
v = √ 2gy
let's calculate
v = √ (2 9.8 0.3)
v = 2,425 m / s
Weight in water = mass of block - mass of volume of displaced water
Initial speed of Gazelle is along x direction and its value will be

also its initial height is given as

Part a)
now from kinematics along Y direction

as we know that





Part b)
distance moved horizontally

as we know that

now we will have

so it will lend at distance of 4 m.
Part c)
final velocity in vertical direction



so net speed will be


