物体间相互作用有三种方式:直接接触、通过媒质、通过场。其中第三种作用方式在中学只研究三种场,即较抽象的重力场、静电场和磁场。总复习时,可从几个方面对它们进行对比。(见下页附表) 现举两个例题复习三种场力。例一在很长的固定绝缘导轨内有一带电的滑块,其质量m=0.1克,电量q=+4×10~(-4)库仑,将其竖直放在相互垂直且沿水平方向的电场、磁场中,如图1所示,场强E=10牛/库。磁感应强度B=0.5 There are three ways in which objects interact: direct contact, passing through media, and passing fields. The third mode of action studies only three fields in secondary schools, namely the more abstract gravity, electrostatic and magnetic fields. When reviewing, they can be compared in several ways. (See the attached table on the next page.) Now consider two examples to review three fields. Example 1 in a long fixed insulation rail has a charged slider, its mass m = 0.1g, power q = +4 x 10 ~ (-4) coulomb, put it vertically and horizontally in the vertical direction In the electric and magnetic fields, as shown in Fig. 1, the field strength E = 10 N/K. Magnetic induction B=0.5