a stone is thrown upward with a velocity of 40m/s.Determine the time of the stone when it is at a height of 10m and is moving downwards.
hf=hi+vi*t-4.9t^2
hi=0,hf=10
solve time t, there are two solutions. Plug each into
vf=vi-9.8t
whichever t gives a NEGATIVE vf is the solution, it is going downward.