$a_{\max }=A{\omega }^2$

$a_{\max }=A{\left(\frac{2\pi }{T}\right)}^2$

$F_w=m{a}_{\max }$

$F_w=F_{s\max }-F_g$

$m{a}_{\max }=F_{s\max }-F_g$

$m{a}_{\max }=1,2F_g-F_g$

$m{a}_{\max }=0,2F_g$

$\cancel{m}{a}_{\max }=0,2\cancel{m}g$

$a_{\max }=0,2g$

$a_{\max }=A\frac{4{\pi }^2}{T^2}|\cdot T^2$

$a_{\max }{T}^2=4{\pi }^{2}A|:4{\pi }^2$

$\frac{a_{\max }{T}^2}{4{\pi }^2}=A$

$A=\frac{0,2g{T}^2}{4{\pi }^2}$

$A=\frac{0,05g{T}^2}{{\pi }^2}$

$A=\frac{0,05\cdot 9,8\frac{\mathrm{m}}{{\mathrm{s}}^2}\cdot {\left(0,8\mathrm{s}\right)}^2}{3,14^2}=\frac{0,49\frac{\mathrm{m}}{\cancel{{\mathrm{s}}^2}}\cdot 0,64\cancel{{\mathrm{s}}^2}}{9,8596}\approx$

$\approx 0,0318\mathrm{m}\approx 3,2\mathrm{cm}$