An object is thrown vertically from a height of #12 m# at # 19 ms^-1#. How long will it take for the object to hit the ground?
Assuming the object was thrown downward, the time taken will be
(we are choosing downward as the positive direction, since both the initial velocity and the acceleration are in that direction)
This one is not so easy to rearrange to have
Rearrange the quadratic into standard form:
Solve the quadratic equation using the quadratic formula, or whichever other method you prefer. This yields two roots, but one makes more sense than the other: