Question

Stie cineva sa rezolve problema asta?

Answer 1

[tex]a)\text{Masa celui de-al doilea fragment este:}\\ m_2=M-m_1 =70-30 =40\ kg\\ \text{Din conservarea impulsului se obtine:}\\ M\cdot v=m_1\cdot v_1+m_2\cdot v_2\\ 70\cdot 300=30\cdot 500+40\cdot v_2\\ 21000=15000+40\cdot v_2\\ 6000=40\cdot v_2\\ \boxed{v_2=150\ \dfrac{m}{s}}[/tex]

[tex]b.\Delta E_c= E_{c1}+E_{c2}-E_c\\ \Delta E_c= \dfrac{m_1\cdot v_1^2}{2}+\dfrac{m_2\cdot v_2^2}{2}-\dfrac{M\cdot v^2}{2}\\ \Delta E_c=\dfrac{30\cdot 250000}{2}+\dfrac{40\cdot 22500}{2}-\dfrac{70\cdot 90000}{2}\\ \Delta E_c=\dfrac{7500000}{2}+\dfrac{900000}{2}-\dfrac{6300000}{2}\\ \Delta E_c= \dfrac{2100000}{2}=1050000\\ \boxed{\Delta E_c= 1,05\ MJ}[/tex]