a stone is tossed doown with a speed of 8 m/ s from the edge of a cliff 63 m high. how long will it take to hit the foot of the cliff?

a= -9.8 m/s ^2

vi= -8 m/s

s= 63m

63m= - 8 m/s(t) + 1/2(9.8m/s^2)(t)^2

does this look right ?

and if so how do i solve for t?

Just confused can someone help me :/