: A stone is thrown downward with an initial velocity of $2\mathrm{.}5$ m$/$s

from a bridge which is H

$=42$ m

above water. The magnitude of the gravitational acceleration is $9\mathrm{.}8$m$/$s$2.$ Take DOWNWARD as positive direction.

Part C $-$ New case: How long $($in seconds$)$ does it take the stone to hit the water? Keep $2$ digits after the decimal point.

You will need to solve a quadratic equation for the time and in general you will get two solutions $-$ one positive, one negative.