Question

quantos joules de energia cinética possui um livro de 1 kg quando é arremessado com uma velocidade de 2 m/s ?

Answer 1

2Joules pois;
EC=m.v²/2
EC=1.2²/2
EC=2J

Answer 2

$\Large\displaystyle\text{ \begin{gathered} \hookrightarrow\boxed{\boxed{\bf{ E_C= 2~J }}} \end{gathered} }$

• Explicação:

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

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{1 \cdot2 {}^{2} }{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{1 \cdot4}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{4}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \boxed{\boxed{\sf{E_C =2 \: J }}} \end{gathered} }$