[tex]\mathbf{Dados}\Longrightarrow m=500\ \text{g}=0.5\ \text{kg};\ \ell=10\ \text{m};\ \tau=200\ \text{N}.[/tex]
[tex]\mathbf{a)\ Velocidade\ de\ propaga\c{c}\tilde{a}o\ de\ um\ pulso}[/tex]
[tex]\boxed{v=\sqrt{\dfrac{\tau\ell}{m}}}\Longrightarrow v=\sqrt{\dfrac{(200)(10)}{0.5}}=\sqrt{4000}[/tex]
[tex]\Longrightarrow v=20\sqrt{10}\ \therefore\ \boxed{v\approx63.25\ \mathrm{m/s}}[/tex]
[tex]\mathbf{b)\ Intensidade\ de\ \tau\ se}\ v=\mathbf{4\ m/s}[/tex]
[tex]v=\sqrt{\dfrac{\tau\ell}{m}}\Longrightarrow \boxed{\tau=\dfrac{mv^2}{\ell}}[/tex]
[tex]\Longrightarrow \tau=\dfrac{0.5(4)^2}{10}\ \therefore\ \boxed{\tau=0.8\ \text{N}}[/tex]
