There is an electric toy formed by a rectangles(8.28cm×5.14cm)and a circle of radius 3cm(with a baby face on it),they connect at Ponint A
And E(as in the construction).If the circle rolls from Point A along the rectangular inner wall(no slip).Finally returns to the original position.
I.Please sketch the circle with a baby face at Position B,C,D respectively.
II.The circle rolls
3
3
revolutions.
有一个电动玩具,它有一个8.28×5.14的长方形盘(单位:厘米)和一个半径为1厘米的小圆盘(盘中画有娃娃脸)它们的连接点为A、E(如图).如果小圆盘沿着长方形内壁,从A点出发,不停的滚动(无滑动),最后回到原来的位置.
(1)请你分别画出小圆盘(娃娃脸)在B、C、D位置示意图.
(2)小圆盘共自转了
3
3
圈.