Question

calcule a energia cinética de uma bola de massa 450g ao ser arremessada e atingir uma velocidade de 18km/h. a)5,625 J b)4,278 J c)6,225 J d)3,690 J e)2, 650 J​

Answer 1

$\Large\displaystyle\text{ \begin{gathered} \hookrightarrow\boxed{\boxed{\bf{ E_C= 5,625~J }}} \end{gathered} }$

• Explicação:

450g=0,45kg

18km/h=5m/s

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{m \cdot{v} {}^{2} }{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{0,45 \cdot5 {}^{2} }{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{0,45\cdot25}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{11,25}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \boxed{\boxed{\sf{E_C =5,625 \: J }}} \end{gathered} }$