A cylindrical container with a bottom area of 100cm2 and a height of 10cm has a pressure of 1200pa on the tabletop after it is filled with water. Now a metal block is suspended by a spring dynamometer and gently immersed in water. When the metal block is immersed in water and stationary, the indication of the spring dynamometer is 4.8n. After the metal block is slowly taken out, the pressure of the container on the tabletop is 1140pa. (take g = 10N / kg) When submerged, the pressure of water on the bottom of container; (2) buoyancy of metal block; (3) density of metal block

A cylindrical container with a bottom area of 100cm2 and a height of 10cm has a pressure of 1200pa on the tabletop after it is filled with water. Now a metal block is suspended by a spring dynamometer and gently immersed in water. When the metal block is immersed in water and stationary, the indication of the spring dynamometer is 4.8n. After the metal block is slowly taken out, the pressure of the container on the tabletop is 1140pa. (take g = 10N / kg) When submerged, the pressure of water on the bottom of container; (2) buoyancy of metal block; (3) density of metal block

(1) Before the metal block is immersed in water, the depth of water in the container is: H = 10cm = 0.1M, the pressure of water on the bottom of the container is: P = ρ GH = 1.0 × 103kg / m3 × 10N / kg × 0.1M = 1 × 103pa; (2) ∵ the pressure of the object on the horizontal plane is equal to its own gravity, ∵ the gravity of draining water when the metal block is immersed: g row = F1-F2 = p1s -