A cube copper block with side length of 0.1M and mass of 4.45kg was placed on the horizontal table, Calculate: 1 the gravity of the copper block 2 please calculate and explain whether the copper block is hollow or solid

A cube copper block with side length of 0.1M and mass of 4.45kg was placed on the horizontal table, Calculate: 1 the gravity of the copper block 2 please calculate and explain whether the copper block is hollow or solid

1、G = mg = 4.45×10 N = 44.5N
2. The volume of copper block v = 0.1 × 0.1 × 0.1 M and 179; = 0.001 m and 179;
When the copper block is solid, the mass m = ρ v = 8.9 × 10 & # 179; × 0.001kg = 8.9kg
∵8.9kg＞4.45kg
The copper block is hollow

When a cube wood block with a side length of 10cm floats on the water surface and weighs 6N, what is the pressure on the upper surface of the block? N? What is the pressure on the lower surface
Please write your own questions, not too messy, to process and ideas, thank you!

If the atmospheric pressure is not included, then the upper surface pressure is 0 and the lower surface pressure is 6N, because the lower surface must support the gravity of the whole block

When a cube wood block with a side length of 10 cm floats on the water surface, and the weight of the block is 6 N, what is the pressure on the upper surface of the block? N? What is the pressure on the lower surface
On buoyancy calculation of Heze 21 middle school students

The upper surface of the block is only subjected to atmospheric pressure, which is f = P 0 * s = P 0 * L ^ 2 = 1.01 * 10 ^ 5 * 0.1 ^ 2 = 1.01 * 10 ^ 3 Newton
There are many algorithms for the pressure and pressure of the lower surface
First, the buoyancy is equal to gravity, f = g = 6N
Buoyancy is the pressure difference between the upper and lower surfaces, so the pressure on the lower surface is
F lower = f upper + F floating = 1.01 * 10 ^ 3 + 6 = 1016 Newton
The pressure on the lower surface is p ﹣ f ﹣ s = 1016 / 0.1 ^ 2 = 1.016 * 10 ^ 5 Pa (the sum of atmospheric pressure and water pressure)