A mass m = 50 g is dropped on a vertical spring of spring constant 500 N/m from a height h = 10 cm as shown in figure (18-E14). The mass sticks to the spring and
executes simple harmonic oscillations after that. A concave mirror of focal length 12 cm facing the mass is fixed with its principal axis coinciding with the line of motion of the mass, its pole being at a distance of 30 cm from the free end of the spring. Find the length in which the image of the mass oscillates.
