The cylinder of mass m is attached to the collar bracket at A by a spring of stiffness k...

The cylinder of mass m is attached to the collar bracket at A by a spring of stiffness k. The collar fits loosely on the vertical shaft, which is lowering both the collar and the suspended cylinder with a constant velocity v. When the collar strikes the base B, it stops abruptly with essentially no rebound. Determine the maximum additional deflection δ of the spring after the impact.