Resposta:
b) 3 m/s
Explicação:
Sabendo que:
[tex]v = 0\\a = 10\;m/s^{2} \\S = 0,45\;m\\S_0=0\\v_0=\:?[/tex]
Usando a fórmula de Torricelli:
[tex]v^2=v_0^2\:+2a\left(S-S_0\right)[/tex]
[tex]0^2=v_0^2\:+2\cdot 10\cdot \left(0-0,45\right)\\\\0=v_0^2\:+20\cdot \left(-0,45\right)\\\\0=v_0^2\:-9\\\\v_0^2\:=9\\\\v_0\:=\sqrt{9}\\\\v_0\:=3\:m/s[/tex]
