[المتفيزق]

ok >>>
It is simple ...
just find the new length of the spring so that you can find the difference or the compression of the spring ( initial length - final length). this is calculated from having the hypothenus (الوتر) from h and the width (295x10-3m) >>> then have the new h : h-79mm and give the hypothenus which is the new length of spring... horrey ... now have the compression... initial length - final length...
now compression gives rise to kx in the other direction and you have mg and F ...all three are in equilbrium at the end ...
so we analyze and give the required value of F
construction of the answer is your career now...
thanks;
abu haitham