题目

Liverpool, my hometown, is a special city. It is so unique that in 2004 it became a World Heritage（遗产）Site.    I recently returned to my home city and my first stop was at a museum on the River Mersey. Blanketed in mist（薄雾），Victorian architecture rose from the banks of the river, responded to the sounds of sea-birds, and appeared unbelievably charming. When I headed toward the centre, I found myself surrounded by buildings that mirror the best palaces of Europe. It is not hard to imagine why, on first seeing the city, most visitors would be overpowered by the beauty星期天，小明和父母来到风景区铁山坪西侧的登山步道登山，如图19甲是铁山坪西侧登山步道示意图，起点文化广场至终点云岭广场全长3.5公里．小明和父母用了100min从起点文化广场到达了终点云岭广场，求：（1）小明和父母登上山全程的平均速度为多少？（2）小明登山至“对弈廊”时，发现水平地面上有由实心圆柱体三墩做成的象棋，如图乙，小明估测了三墩的高约0.2m，查到了三墩的密度约为2.5×103kg/m3，取g=10N/kg，请你计算三墩对水平地面的压强约为多少？