Physics help please..quiz 2morrow and i really don't understand this question??

im studying for a quiz tomorrow and i don't understand this question.

A spring-driven dart gun propels a 10 gram dart. It is ****** by exerting a force of 20N over a distance of 5.0 cm. How fast will the dart leave the gun? Find the speed?

and help or somewhat of an explanation on what formula/what to do? Any help is greatly appreciated!! :)

Physics help please..quiz 2morrow and i really don't understand this question??

Hooke's Law can be used to solve this problem.

F=kx; wherein k is the spring constant

20N/0.05m = k

k = 400N/m

A second equation can then be applied to find the veolcity of the spring at its equilibrium position. The dart will have the same velocity with the spring.

v=x times squareroot of k/m; where x is the displacement, m is the mass attached to the spring and k is the spring constant

velocity of the dart when it leaves the gun is 10m/s.

Physics help please..quiz 2morrow and i really don't understand this question??

ask ur teach