Question

3)Calcule a energia cinética de uma bola de massa 800g ao ser arremessada e atingir uma velocidade de 5 m/s. *
10 pontos
a) 10000 J
b) 1000 J
c) 100 J
d) 10 J
e) 1 J

Answer 1

E=mv^2/2

E=0,8x(5)^2/2

E=(0,8x25)/2

E=20/2

E=10J

Answer 2

$\Large\displaystyle\text{ \begin{gathered} \hookrightarrow\boxed{\boxed{\bf{ E_C= 10~J }}} \end{gathered} }$

• Explicação:

800g=0,8kg

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

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{0,8 \cdot5 {}^{2} }{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{0,8 \cdot25}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{20}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \boxed{\boxed{\sf{E_C =10 \: J }}} \end{gathered} }$