Fast. do first question only and show work thx.

Y = -0.01x^2 + 0.5x + 3

when the height y = 8 
-0.01x^2 + 0.5x + 3 = 8
-0.01x^2 + 0.5x - 5 = 0

x =  13.82 and x = 36.18 so the ball is at least 8 ft high   from 13.82 and 36.18 feet inclusive.- from the player.

If the player is 30 ft from the net then the ball is likely to go over the net.