So this was just a practice question that I had to do before my test for quadratics.
a) There are no zeros: the vertex of the parablola is (0,24) and this parabola rises from there.
Another way: setting the equation equal to zero: 0.005x2 + 24 = 0
---> 0.005x2 = - 24
---> x2 = - 24/0.005
---> x2 = - 4800 (there is no real solution)
b) 24 meters because this is the minimum value of the quadratic.
Bonus: Setting the equation equal to 30: 0.005x2 + 24 = 30
---> 0.005x2 = 6
---> x2 = 6/0.005
---> x = sqrt(1200) = 34.64
Total distance: 34.64 ·2 = 69.3 meters.