Higher Physics homework help?

Question

Homework question I got 24 seconds but i dont think it is right. Can someone please check and if it isnt, can you tell me which formula i was meant to use?

"If a stone is thrown vertically down a well at 5ms^-1. Calculate the time taken for the stone to reach the water surface 60m below."

Thanks :)

Answer 1

Kinematics equation: d = Vi*t + 0.5*a*t^2

Vi (initial velocity) = -5 (m/s)

d (displacement) = -60 m

a (gravitational acceleration) = -9.8 m/s^2

-60 m = -5 (m/s)*t + 0.5*(-9.8 m/s^2)*t^2

Solve for t using quadratic equation get 3.026 sec