Kinematics in 1D: Determining Velocity After 0.5s

[karkrash]

1. A stone is thrown with an initial velocity of +7.0 m/s. The acceleration of the stone is a constant and has the value of -9.81m/s^2.What is the velocity of the stone after 0.5s?



2. Homework Equations
vf=vi+at?
i have no idea



3. The Attempt at a Solution
i can't find the right equation to put this in

 

[Doc Al]

What direction is it thrown? Never mind--your title suggests 1D motion, so I presume straight up.

You have the correct equation. Use it!