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题目1将一个边长2厘米的金属正方块放进用一块塑料片挡住下端的玻璃筒,用手托住塑料片将筒插入水中较深位置,放开托塑料片的手,如图1所示将筒慢慢上移,当筒的下端离水面8厘米时,金属块与塑料片一起落于水中.若筒的横截面积是10厘米~2,塑料片重力不计,求金属的密度.错解认为此时金属和水对塑料片的压强
Question 1 Place a square metal square with a side of 2 cm in length into a glass tube with a piece of plastic blocking the lower end. Hold the plastic sheet by hand to insert the tube into the deeper part of the water and let go of the plastic sheet, as shown in Figure 1. The barrel is slowly moved upwards. When the lower end of the barrel is 8 centimeters from the water surface, the metal block and the plastic piece fall into the water. If the cross-sectional area of the barrel is 10 centimeters to 2, the gravity of the plastic sheet does not count, and the density of the metal is required. The wrong solution considers the pressure of metal and water on the plastic sheet at this time