Suggest one material that is used to make the trampoline surface.
Explain your answer.

Polypropylene is the safest material for trampoline mats in the trampoline market. The fibers are heavily woven to make a buoyantly webbed fabric. The fabric is then thermally interlocked to provide a smoother stabilized surface that can withstand constant flexing and stress.

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be

1/0.14nm = 10^10/1.4 a lot