Lianyungang underwater photography

(1) As can be seen from the figure, the calibration value of the spring dynamometer is 0.2N, the gravity of the object is G=3.2N, and the indicator f' of the spring dynamometer is 2N after being immersed in the wood block.

Buoyancy of an object:

F float =G-F'=3.2N-2N= 1.2N，

Underwater volume of Block A at rest:

Row V =F floating ρ G =1.2n1.0×103kg/m3×10n/kg =1.2×10-4m3;

(2) Take the container, water and object as a whole, and the force is balanced. The pressure on the desktop is F total =F floating +G container +G water.

Gravity of container and water:

g = mg = 1kg× 10N/kg = 10N，

After the wooden block is immersed in water, the pressure of the container on the desktop:

P=F Total S=G+F Floating S =10n+1.2n100×10? 4m2= 1 120Pa。

Answer: (1) When Block A is at rest, the submerged volume is1.2×10-4m3;

(2) At this time, the pressure of the beaker on the horizontal plane is 1 120 Pa.