Answer:
This looks like the same problem you sent already, so I will be copying my original answer.
Function is h(s) = 40-2s
H(2) = 40-(2)(2)
H(2) = 40-4 = 36
Because the function represents height and time, we can say after 2 seconds the height in feet is 36. --> For H(2)
We need to set 40-2s = 30 for h(s)=30
30-40 = -10
-2s = -10 Divide both sides
s = 5