Velocity Acceleration and Gravity

[Tnn Ace03]

In physics we are studying velocity acceleration and gravity. Either i am stupid or am not understanding this, but i just can't seem to understand the material. for example i don't know which formula to use for which story problem, for example(Please do not answer the problem) With a cruising speed of 2.30 X 10 to the third km/h, the french supersonic passenger jet concorde is the fastest commercial airplane. Suppose the landing speed is 20.0 precent of the cruising speed. Over what distance(meters) does the plane travel to a complete stop if its deceleration has a magnitude of 5.80m/s squared

I know that i have to get the km/h into meters per second, but i don't know how to solve it.

Any help or tips would be greatly appreciatied

 

[neutrino]

To solve any problem, at least in the initial stages of education, look at what data you are supplied with, then use the appropriate formula that connects these data. And don't bring in new variables unncessarily.

Back to the problem...you are provided with the initial velocity ("landing speed") of the aircraft, the final velocity, and the decelaration ("negative accelaration"). Now, what formula can you use to find the distance traveled given the above information?