Resposta :
[tex]\large\boxed{\begin{array}{l}\sf F=m\cdot a\\\sf 60=4a\\\sf 4a=60\\\sf a=\dfrac{60}{4}\\\\\sf a=15\,m/s^2\end{array}}[/tex]
[tex]\large\boxed{\begin{array}{l}\sf F=m\cdot a\\\sf 60=4a\\\sf 4a=60\\\sf a=\dfrac{60}{4}\\\\\sf a=15\,m/s^2\end{array}}[/tex]