[Ether]

A massless spring of free length L and spring constant K is stretched until a desired force F is achieved. A mass M is attached to the stretched spring, and the spring is then allowed to accelerate the mass until the spring length is L2.

Find a closed-form solution for the speed of the mass when the spring length is L2 (where L2>L). Ignore friction and gravity. Use the solution to explore the effect of small changes in L and K (with F, M, and L2 held constant).