Hmm! If u is the initial upward velocity and g is the gravitational acceleration, then
\(\frac{dh}{dt}= u-g\times t\)
This means that
\(h(t)=u\times t-\frac{g}{2}\times t^2\)
So, either u is 54 or the initial velocity is 5 ft/sec. Which is it?
(Also, it looks like g = 24 ft/sec^2 here.)
