It's Sunday morning. The students of Class 3 are giving their classroom a good cleaning. Miss Huang, their teacher, is working with them. The children are busy. Some are carrying water, some are cleaning the windows, others are sweeping the floor. Zhang Hua is putting up a map on the wall. It is a map of China. Wang Fei and Wei Qing are mending some broken chairs. The children are listening to the radio while they are working. The classroom looks nice and bright after the cleaning. The children are very happy. They go home for lunch at noon.

如图，在等腰直角三角形ABC中，∠BAC=90°，AC=8 $\sqrt{2}$ cm，AD⊥BC于点D，点P从点A出发，沿A→C方向以 $\sqrt{2}$ cm/s的速度运动到点C停止，在运动过程中，过点P作PQ∥AB交BC于点Q，以线段PQ为边作等腰直角三角形PQM，且∠PQM=90°（点M，C位于PQ异侧）．设点P的运动时间为x（s），△PQM与△ADC重叠部分的面积为y（cm²）