Question

1) Qual a energia cinética de uma moto com massa 400 kg que viaja a 8m/s?

2) Qual a energia cinética de um objeto com massa 6 kg que que se movimenta com velocidade de 4m/s?

3) Calcule a energia cinética de uma bola de massa 0,8 kg ao ser arremessada e atingir uma velocidade de 7 m/s.

4) Qual a energia cinética de uma pedra de massa 1,2 kg ao ser arremessada e atingir uma velocidade de 6 m/s.

Answer 1

Resolução abaixo

• Explicação:

1 )

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

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{400 \cdot8 {}^{2} }{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{400 \cdot64}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{25600}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \boxed{\boxed{\sf{E_C =12800 \: J }}} \end{gathered} }$

2 )

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

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{6 \cdot4 {}^{2} }{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{6 \cdot16}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{96}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \boxed{\boxed{\sf{E_C =48 \: J }}} \end{gathered} }$

3 )

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

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

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

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

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

4 )

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

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{1,2 \cdot6 {}^{2} }{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{1,2 \cdot36}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{E_C = \dfrac{43,2}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \boxed{\boxed{\sf{E_C =21,6 \: J }}} \end{gathered} }$