单项选择题三块平行放置的金属板A、B、C其面积均为S,AB间距离为x,BC间距离为d,设d极小,金属板可视为无限大平面,忽略边缘效应与A板的厚度,当B、C接地(如图),且A导体所带电荷为Q时,则B板上的感应电荷为 A、 B、 C、 D、
单项选择题One mechanic pushes a 2.50×103-kg car from rest to a speed of v, doing 5 000 J of work in the process. During this time, the car moves 25.0 m. Neglecting friction between car and road, find the horizontal force exerted on the car. ()