[Ether]

Good stuff.

In post #2, lemiant used energy conservation to find the solution*.

In post #6, dan2915 used the equations for simple harmonic motion.

Let me add a third way: use Newton's 2^nd Law:

F = -k*x = M*a = M*(dV/dt) = M*(dx/dt)(dV/dx) = M*V*(dV/dx)

=> M*V*(dV/dx) = -k*x

=> V*dV = -(k/M)*x*dx

Integrate the left side from V=0 to V=V₂, and the right side from x=-F/k to x=(L-L₂), and solve for V₂

This Quiz was inspired by post #5 in this thread.


*neglecting the error in the final step