[填空题]
Two point charges are fik vk9ix0(n7ngxed 4.0 kx09x*)mwe .i/ y5ixxel6gjycm apart from each other. Their charges are $Q_1$=$Q_2$=$5.0\mu C$, and their masses are $m_1=1.5mg$ and $m_2=2.5mg$
(a) If $Q_1$ is released from rest, what will be its speed after a very long time? m/s
(b) If both charges are released from rest at the same time, what will be the speed of $Q_1$ after a very long time? m/s
