There is a long, wide, high 20cm, 10cm, 5cm rectangular wood block. When it is placed horizontally, vertically, and laterally, the ratio of its pressure on the desktop () and the ratio of its pressure ()

1. Horizontal, vertical and side, the mass of the wood block remains unchanged, the gravity remains unchanged, and the pressure on the desktop remains unchanged, so it is 1:1:1
2. The pressure is equal to the pressure / force area, so the ratio of pressure is equal to the inverse ratio of force area
The ratio of length to width to height is 4:2:1, so the ratio of pressure is 1 / 4 * 2:1 / 2 * 1:1 / 4 * 1 = 1:4:2

The brick is 25cm in length, 10cm in width and 5cm in thickness. The brick is placed horizontally, laterally and vertically on the horizontal ground, and its pressure ratio to the ground is And the pressure ratio is ．

When the object is placed on the horizontal ground, the pressure is equal to gravity, that is, the ratio of pressure is 1:1:1; when the object is placed horizontally, the contact area S1 = 25cm × 10cm = 250cm2; when the object is placed laterally, the contact area S2 = 25cm × 5cm = 125cm2; when the object is placed vertically, the contact area S3 = 10cm × 5cm = 50cm2; when the weight of the brick is g, the ratio of pressure is P1: P2: P3 = GS1: GS2: GS3 = 1250:1125:150 = 1:2:5, so the answer is: 1:1, 1:2 ：5．

There is a square iron block with a mass of 7.9kg, which is placed in the middle of a horizontal desktop with an area of 1m square. What is the pressure and pressure on the desktop

V = m /ρ=7.9kg/7900kg/m3=0.001m3
Side length = 0.1M area s = 0.01m2
Pressure f = g = mg = 79n
Pressure P = f / S = 7900pa

There is a long, wide, high 20cm, 10cm, 5cm rectangular wood block. When it is placed horizontally, vertically, and laterally, the ratio of its pressure on the desktop () and the ratio of its pressure ()