A hammer and a feather are dropped at the same time from 4 feet, in a under a vacuum by an astronaut under the moons gravity.....
initial conditions: ds/dt=0 and s=4 when t=0.
So, I find ds/dt, is -5.2T+c, and v(0)=4.
I want to find t when S(t)=0
I want t when s(t)=0.