"will isabella be able to spray ferdinand if the water is flowing out of the hose at a constant speed v 0 of 3.5 meters per second? assume that the hose is pointed parallel to the ground and take the magnitude of the acceleration g due to gravity to be 9.81 meters per second, per second.":

The question is incomplete.

Here is the complete question (only part A): 

Two children, Ferdinand and Isabella, are playing with a water hose on a sunny summer day. Isabella is holding the hose inher hand 1.0 meters above the ground and is trying to spray Ferdinand, who is standing 10.0 meters away.
Part A

Will Isabella be able to spray Ferdinand if the water is flowing out of the hose at a constant speed Vo of 3.5 meters per second? Assume that the hose is pointed parallel to the ground and take the magnitude of the acceleration due to gravity to be 9.81 meters per second, per second.

No. Since the water jet runs 1.58 m before falling into the ground, it cannot spray Ferdinand who is 10.0 m away.

Explanation:

1) Data: 
yo = 1.0m
Vox = 3.5 m/s
Voy = 0
x = 10.0 m

g = 9.81 m/s²

2) Type of motion and formulas

Parabolic motion
y = yo + Voy×t - g×t² / 2
x = Vox × t

3) Solution:

i) From y = yo + Voy×t - g×t² / 2 calculate t until the water reaches the ground (y = 0).

From the data yo = 1, and Voy = 0

0 = 1.0 - 4.905t² ⇒ t = √ (1.0 / 4.905) = 0.45 s

ii) Calculate x using t = 0.45s 

From the data Vox = 3.5m/s

x = Vox × t = 3.5m/s × 0.45s = 1.58 m

iii) Conclusion: since the water jet runs 1.58 m before falling into the ground, it cannot spray Ferdinand who is 10.0 m away.