例题如图1,质量为m的跨接杆可以无摩擦地沿水平的平行导轨滑行,两轨间宽度为L.导轨与电阻R连接,放在竖直向上的匀强磁场中,磁感应强度为B,杆的初速为v0,杆和导轨的电阻不计.试求杆到停下来所滑行的距离.此题是力与电磁感应综合的一道题目,一般解题思路是利用微元法与动量定理相结合来分析求解,但对于高中学生来说,由于数学知识的不完善,每每提到微元法,就会感到莫名的恐惧,造成理解上的困难.本文拟利用高中学生比较容易接受 Examples in Figure 1, the mass of m jumper bar can be frictionless horizontal parallel rail glides, the width between the two rails L. R rail and resistance R connection, on the vertical uniform magnetic field, the magnetic induction intensity of B, the initial velocity of the rod v0, the resistance of the rod and the guide rail .To find the rod to stop the sliding distance.This problem is a combination of force and electromagnetic induction problem, the general problem-solving idea is the use of the micro element method and the momentum theorem But for high school students, because of imperfect mathematical knowledge, often referred to the micro-element method, it will feel inexplicable fear, resulting in understanding difficulties.This paper intends to use high school students more easily accepted