3. A ball is thrown into the air with an initial upward velocity of 46ft/s. Its height (h) in feet after t seconds is given by the function h = -16t^2 + 46t + 6. After how many seconds will the ball hit the ground?

A. 3
B. 4
C. 5
D. 6

I think D, if i'm wrong can one of you guy help me thanks

1 answer

well, did you check it?

-16*36 + 46*6 + 6 = -294

So, stop guessing and do the math!

h = -2(8t^2-23t-3)
= -2(8t+1)(t-3)

So now what do you think?