Given :
A spring whose spring constant is 850 N/m is compressed 0.40 m.
To Find :
The maximum speed it can give to 0.50 kg ball.
Solution :
We know, Kinetic energy = Energy stored in spring
[tex]\dfrac{mv^2}{2}= \dfrac{kx^2}{2}\\\\v= x\sqrt{\dfrac{k}{m}}\\\\v = 0.40\times \sqrt{\dfrac{850}{0.50}}\\\\v = 16.49\ m/s[/tex]
Hence, this is the required solution.