The density of iron is the third power of 7.9 × 10. There is an iron ball with a mass of 1.59kg and a volume of 300cm / m3. There are three methods to find the solid or hollow

The density of iron is the third power of 7.9 × 10. There is an iron ball with a mass of 1.59kg and a volume of 300cm / m3. There are three methods to find the solid or hollow

Solution 1: find the density of the ball from ρ = m / v
ρ sphere = m / v = 1590g / 300cm & # 179; = 5.3g/cm & # 179; < ρ iron;
Therefore, the iron ball is hollow
Solution 2: get m = ρ V from ρ = m / V, and calculate 300cm & # 179
M Fe = ρ Fe, v = 7.9g/cm, × 300cm, = 2370g ＞ 1590g;
Therefore, the iron ball is hollow
Solution 3: get v = m / ρ from ρ = m / V, and find the volume of 1590g iron
V iron = m / ρ iron = 1590g / (7.9g / cm # 179;) = 201cm # 179; < 300cm # 179;;
Therefore, the iron ball is hollow

The mass of an iron ball is 158g, and its volume is 30 cubic centimeter
The mass of an iron ball is 158g
It has a volume of 30 cubic centimeters, and it can judge whether it is hollow or solid (ρ Fe = 7.9 ╳ 10 cubic meters per kilogram)

Assumed solid
ρ=m/v
V = m / ρ = 158 / 7.9 = 20 cc
It's smaller than the actual volume, so it's hollow

The iron ball with a volume of 5 * 10 to the power of - 3 M & # 179; has a mass of 25kg and is hollow. How much is the volume of the hollow part? The hollow part is full (see the title for details.)
The mass of an iron ball with a volume of 5 * 10 to the power of - 3 M & # 179; is measured to be 25 kg. Try to judge whether the ball is hollow or solid. (P = 7.8 * 10 to the power of 3 kg / M & # 179;)
Solution 1: comparative density method
Solution 2: comparative volume method
Solution 3: comparative quality method
If it is hollow, what is the volume of the hollow part? If the hollow part is filled with water, what is the total mass of the ball?
(please write down the detailed process! Complete and correct + 80; complete + 40; correct + 40!)

Solution 1: comparative density method: P Fe = 25 / 5 * 10 ^ (- 3) = 5 × 10 & # 179;

The mass of a bag of rice is 25kg. The density of this kind of rice is 1.5 times the cubic kilogram per cubic meter. How big is the bag of rice? Is the unit cubic meter or cubic centimeter

Cubic meter