A block of mass m = 1kg is dropped onto a spring of constant $\text{k}=400\text{N/m}$  from a height ‘h’. The second end of the spring is attached to a second block of mass M = 4kg as shown. The minimum value of h so that the block 4 kg bounces off the ground if the block of mass 1kg sticks to the spring immediately after it comes into contact with it is$\frac{\alpha }{10}\text{m}$ ,where $\alpha =$ ............