Question

A Energia cinética de uma bola de massa 0,8 kg ao ser arremessada e atingir uma velocidade de 7m/s: *

a) 3,2 J
b) 4,1 J
c) 5,6 J
d) 7,0 J
e) 7,5 J​

Answer 1

$\Large\displaystyle\text{ \begin{gathered} \hookrightarrow\boxed{\boxed{\bf{ E_C= 19,6~J }}} \end{gathered} }$

• Explicação:

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

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{0,8 \cdot7 {}^{2} }{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{0,8 \cdot49}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{39,2}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \boxed{\boxed{\sf{E_C =19,6 \: J }}} \end{gathered} }$