[tex] \vec{T_y}+\vec{G}=0\implies T\sin\alpha=mg\implies T=mg/\sin\alpha\\\\ \sin\alpha=\sqrt{1-\cos^2\alpha}\implies T=\dfrac{mg}{\sqrt{1-r^2/(l+r)^2}}\approx 24,5N\\\\\\ \vec{T_x}+\vec{N}=0\implies N=T\cos\alpha\\\\ N=mg\text{ctg }\alpha=\dfrac{mgr}{(l+r)\sqrt{1-r^2/(l+r)^2}}=\dfrac{mgr}{\sqrt{l^2+2lr}}\approx 4,9N [/tex]
