给我讲讲这题---**Question 3** **Source:** [2022 湖南常德] **Question Stem:** 如图所示, 物体重 20 N, 它与竖直墙面的接触面积是 0.2 dm², 现用 30 N 的水平力把物体按在墙上, 墙面受到的压强是_________ Pa, 物体受到的摩擦力是_________ N. **Diagram Description:** * **Type:** Simple physics diagram showing forces acting on an object against a wall. * **Main Elements:** * A square object. * A vertical wall indicated by vertical hatching lines on the right side. * The object is positioned against the vertical wall. * A horizontal arrow labeled "F" points from left to right, towards the object and the wall, representing the horizontal force pushing the object against the wall. * **Relative Position:** The object is pressed against the vertical wall by the force F. **Given Information:** * Object's weight: 20 N * Contact area with the vertical wall: 0.2 dm² * Horizontal force applied: 30 N **Quantities to Find:** * Pressure exerted on the wall: (blank) Pa * Friction force acting on the object: (blank) N