What is the Final Velocity After Deceleration?

[ScienceGirl90]

Homework Statement

An 9.30 kg body moving at 9.30 m/s begins to decelerates uniformly. After 9.30 s the body is 9.30 m from the location were it started to decelerate.
What is the final speed of the body 9.30 s after it started to decelerate?

Homework Equations

I'm not sure what equation to use.

The Attempt at a Solution

I'm not sure how to tackle this problem to find final velocity when I only have initial velocity, time, and distance. Help please!

 

[PhanthomJay]

You can use a couple of the kinematic equations, but there is a single simple kinematic equation for constant acceleration that relates initial velocity, final velocity, displacement, and time. Which one is that?

 

[ScienceGirl90]

Would that be the d=1/2(v_f+v_i)t ?
I wasn't given that equation on my handout but I looked it up.

 

[PhanthomJay]

Speed is the magnitude of the velocity. Yes, that is the right equation; solve it for V_f; the magnitude of V_f is its speed. Speed is not distance divided by time. Distance divided by time is average speed. You are looking for the instantaneous speed.