(1) A brick with a thickness of 5cm and a density of 2.5 × 103kg / m3 is placed on the horizontal ground. As shown in figure (a), what is its pressure on the ground? (2) Using this kind of brick to build a wall, the gap between the upper and lower layers of brick and between the brick and the horizontal wall base is filled with cement slurry with thickness of 1cm and density of 2.0 × 103kg / m3, as shown in figure (b). If the maximum pressure that the wall base can bear is & nbsp; 4.35 × 105Pa, how high can the wall be built at most? (g = 10 N / kg)

(1) A brick with a thickness of 5cm and a density of 2.5 × 103kg / m3 is placed on the horizontal ground. As shown in figure (a), what is its pressure on the ground? (2) Using this kind of brick to build a wall, the gap between the upper and lower layers of brick and between the brick and the horizontal wall base is filled with cement slurry with thickness of 1cm and density of 2.0 × 103kg / m3, as shown in figure (b). If the maximum pressure that the wall base can bear is & nbsp; 4.35 × 105Pa, how high can the wall be built at most? (g = 10 N / kg)

(1) The pressure of the wall to the horizontal ground: P = FS = GS = MGS = ρ VGS = ρ SHGs = ρ GH, the pressure of this brick to the ground: P = ρ 1GH = 2.5 × 103kg / m3 × 10N / kg × 5 × 10-2m = 1250pa; (2) the maximum height of the wall is h, ∵ the thickness of the brick is 5cm, the thickness of the cement mortar between the brick joints is 1cm, ∵ the total height of the brick H1 = 56h, the height of the cement mortar h2 = 16h, and the pressure of the wall to the wall base shall not exceed 4.35 × 1 5 × 103kg / m3 × 10N / kg × 56h + 2.0 × 103kg / m3 × 10N / kg × 16h ≤ 4.35 × 105Pa, the solution is: H ≤ 26114.5m = 18m, that is, the wall can build 18m at most