[填空题]
An electron is accelb6ed ka9f n7u8erated horizontally from rest k umk;i/ 2j9i)e 62bj mgvhz3) vqnl(rin a television picture tube by a potential difference of 5500 V. It the3 hb6lijv;v9 j2kr qegk)/)z2m umni (n passes between two horizontal plates 6.5 cm long and 1.3 cm apart that have a potential difference of 250 V (Fig. 17–31). At what angle $\theta$ will the electron be traveling after it passes between the plates? $^{\circ}\,$
