It's really poor form to use 'h' to mean two different things in two different
places in the same formula. Fortunately, we know what you mean.
H = h + vt - 16t²
You have said that ...
initial height = 5 feet
initial
velocity = 20 feet per second, no direction given
time = 1 second
Since you gave us the magnitude of the initial velocity but not its direction,
there are a huge number of possibilities. I'll focus only on two of them:
20 feet per second straight down, and 20 feet per second straight up.
Initial velocity is downward:
H = (5) + (-20) (1) - 16 (1)²
H = 5 - 20 - 16 = 5 - 36 = 31 feet underground after 1 second
Initial velocity is upward:
H = (5) + (20) (1) - 16 (1)²
H = 5 + 20 - 16 = 25 - 16 = 9 feet above ground after 1 second
