用橡皮筋将一小球悬挂在小车的架子上， 系统处于平衡状态，现使小车从静止

Use a rubber band to suspend a small ball on the rack of the car. The system is in a balanced state. Now the car accelerates from the standstill to the left. The acceleration gradually increases from zero to a certain value. Deviates from the vertical by an angle (the rubber band is within the elastic limit). The height of the ball compared to when it is stable in a vertical position

With a rubber band to hang a small ball on the shelf of the trolley, the system is in a balanced state, now the trolley from rest to the left acceleration, acceleration from zero to a certain value, and then maintain this value, the ball steadily deviates from the vertical direction of an angle (rubber band within the elastic limit). The height of the small ball compared to the position that stabilizes the vertical position

Use rubber band to hang a small ball on the frame of the car, the system is in a balanced state, now make the car accelerate from static to left, the acceleration gradually increases from zero to a certain value, and then keep this value, the small ball stably deviates from a certain angle in the vertical direction (rubber band is within the elastic limit). The height of the ball compared to the height when it is stable in the vertical position