不计重力的带电粒子沿垂直匀强磁场方向运动时将受到洛伦兹力的作用做匀速圆周运动,这是常见问题。若粒子除受洛伦兹力外还受到其他力,则高中学生能处理的问题无非是洛伦兹力与其他力平衡做匀速直线运动或所有其他力平衡后合力为洛伦兹力做匀速圆周运动两种情况。若是出现复杂的曲线运动时,由于速度的大小和方向时刻在改变,洛伦兹力就时刻改变,要求解此类问题的运动情况,高中阶段几乎没有办法解决。但在物理竞赛中,经常会碰到这种题型,处理方法是为带电粒子配上一对大小相等方向相反的速度(其实合速度等于零)或对带电粒子的初速度进行分解,把复杂的曲线运动分解为匀速直线运动和匀速圆周运动的合成,这两种运动是高中生所熟知的。这实际上是借助等效原理和运动的合成分解原理,在全新的数理模型基础上简化了问题,这种方法常称为“配速法”。 It is a common problem that the charged particles that do not contain gravitation move along the direction of the uniform and uniform magnetic field with constant circular motion due to the Lorentz force. If the particle is subject to other forces besides Lorentz force, then the problem that high school students can handle is nothing more than a Lonzent force with other force balance to do a uniform linear motion or all other force balance forces together to make a Lorentz force uniform circle Two cases of exercise. If there is a complicated curve movement, the Lorentz force will momentarily change due to the change of the speed and the direction time, and there is almost no solution to the problem of the movement of such problems. However, in physical competition, often encounter this type of problem, the method is to deal with the charged particles coupled with a pair of the same size in the opposite direction (in fact, the speed is equal to zero) or the initial velocity of charged particles decomposition, the complex Curvilinear motion is decomposed into a combination of uniform linear motion and constant circular motion, both of which are well known to high school students. This is actually by virtue of the principle of equivalent and synthetic motion decomposition principle, based on a new mathematical model to simplify the problem, this method is often referred to as “speed method.”