How do I calculate the Velocity when only given the force and weight?

[camel-man]

I do not know how to calculate the velocity of a 50.0g steel ball shot from a slingshot with a 120N/m spring constant when pulled back 35cm and released.

Can someone help me with the formulas to use?

 

[mfb]

As this looks like homework, I moved the thread to the homework section.

Did you try energy conservation?

 

[Sixty3]

The elastic potential energy is given by $PE=\frac{1}{2}kx^2$

The potential energy will be converted to kinetic energy given by $KE=\frac{1}{2}mv^2$