把一只小鸟放在密闭的大玻璃盒内,再把玻璃盒放在天平的一只秤盘上。当小鸟停留在盒底时,在天平的另一只秤盘上放上砝码,使两边互相平衡。当小鸟从盒底加速向上飞时,天平两边还会不会平衡呢? “小鸟加速向上飞后,不再与盒子接触,盒子这边的重量就减轻了,放盒子的秤盘一定会往上翘。”不少读者可能会这样回答。 Put a bird in a closed glass box and place the glass box on a weighing pan of the balance. When the bird stays on the bottom of the box, place a weight on the other scale of the balance to balance the two sides. When the birds speed up from the bottom of the box when flying, balance on both sides will not balance it? “After the bird accelerated to fly up, no longer contact with the box, the weight on the box side to reduce the box will put the weighing pan will Upturned. ”Many readers may answer this.