I don't think_____________difficult for a Chinese student to master a foreign language within five years A.that B.it C.too D.very 答案:B
在如图所示,水平向右的匀强电场中,有a、b、c三点,ab=10 cm,bc=15 cm,其中ab沿电场方向,bc和电场方向成53°角.一个电荷量为q=4×10-7 C的正电荷从a点移到b点,静电力做功为W=1.2×10-5 J,已知sin53°=0.8.求:
(1)匀强电场的电场强度是多少;
(2)a、c两点的电势差Uac;
(3)该正电荷从a点移到c点,静电力所做的功为多少?