Problem 2:Conservation of Cars

Conservation of charge in one dimension is similar to conservation of cars on a road. Cars move along the road with car density lambda and speed v which, in general, are functions of position. (a) The continuity equation requires that lambda divided by v at all points on the road is the same. (b) Nothing in the continuity equation needs to be modified if there is a factory which adds cars to the road and/or a parking garage which takes them off the road.