A football is kicked with a speed of 18 m/s at an angle of 65° to the horizontal.

How long is the football in the air? Neglect air resistance

Would I use the equation
y=y0 + voy t -1/2gt^2 ?

2 answers

that is correct. All you care about is the height.
Yes, with voy = 18 sin65 = 16.31 m/s

Set y = yo and solve for t

gt/2 = voy
t = 2*voy/g