#1) 4.445 ft
#2) yes
Step-by-step explanation
#1) The maximum height is the y-coordinate of the vertex. We first find the axis of symmetry, given by x=-b/2a:
x=-0.17/2(-0.005) = -0.17/-0.01 = 17
Plugging this into the equation,
y=-0.005(17²)+0.17(17)+3 = 4.445
#2) Substituting 30 into the equation,
y=-0.005(30²) + 0.17(30) + 3 = 3.6
The ball will 3.6 in the air, so yes, it will clear the 3 ft tall net.