Question

Ec1=Ec2 m1/m2=1,44 v1=5m/s v2=?

Answer 1

$E_{c1}=E_{c2}=E_c \\ \frac{m_1}{m_2}=1,44 \\ v_1=5 \ m/s \\ \boxed{E_c=\frac{m \cdot v^2}{2}} \\ m_1 \cdot v_2^2=2E_c; \ \ \Rightarrow v_2=\sqrt{\frac{2E_c}{m_2}} \\ \ \ E_c=\frac{m_1 \cdot v_1^2}{2} =\frac{25 \ (m/s)^2 \cdot m_1}{2} \\ \\ \Rightarrow v_2=\sqrt{\frac{2\frac{25 \ (m/s)^2 \cdot m_1}{2}}{m_2}}; \ \ m_1=1,44m_2 \\ \\ \Rightarrow v_2=\sqrt{\frac{25 \ (m/s)^2 \cdot 1,44m_2}{m_2}}=\sqrt{\frac{25 \cdot 1,44}{1}} \ m/s=\sqrt{36} \ m/s \\ \Rightarrow \boxed{\bold{v_2=6 \ m/s}}}$