Answer:
sqrt(10/16)
Step-by-step explanation:
h0 is the height it was dropped from, and the question says we drop a ball from a height of 10, so we have h0 = 10.
So now we have -16t^2 + 10 and we want to know when the height is 0, so when -16t^2 + 10 = 0. So it's just algebra, and solving for t will give us the time.
-16t^2 + 10 = 0
-16t^2 = -10
t^2 = 10/16
t = sqrt(10/16)
Solving algebraically makes the negative an answe too, but you can't have a negative time. Go ahead and plug in to double check though.