Is my answer correct? And if not which one is the correct answer and explain please :)

Emma hits a golf ball from the ground with an initial vertical velocity of 40 m/s. Which equation can be used to find the time, t, it takes for the ball to reach the ball to reach the ground?
–4.9t2 + 40t = 0
–4.9t2 + 40 = 0
–16t2 + 40t = 0

Question

Is my answer correct? And if not which one is the correct answer and explain please :) 

  Emma hits a golf ball from the ground with an initial vertical velocity of 40 m/s. Which equation can be used to find the time, t, it takes for the ball to reach the ball to reach the ground? 
       –4.9t2 + 40t = 0
        –4.9t2 + 40 = 0
        –16t2 + 40t = 0<-----
        –16t2 + 40 = 0

acxbox22 · Answer

the -16t^2 formula is used for feet
converted nito meters it would be -4.9t^2 but the +40t part is right