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[physical density of the second day of junior high school] when selecting seeds with salt water, the density of salt water should be higher
Divide the mass of salt water by the volume of salt water, calculate the density of salt water, and then compare it with the density of salt water to be prepared. It is found that it does not meet the requirements, and 500 grams of water needs to be added
It is reliable and easy for farmers to select seeds with salt water. The density of salt water is required to be 1.1 × 103kg / m3. Now 500ml salt water is prepared and its mass is 0.6kg. Does this salt water meet the requirements? If not, should salt or water be added? How much more?
The density of the sample: ρ sample = MV = 600g500cm3 = 1.2g/cm3, ∵ 1.2g/cm3 ＞ 1.1 × 103kg / m3, ∵ does not meet the requirements, water should be added; set the amount of water to be added as Ag, because the density of water is 1g / cm3, so the volume of water to be added is acm3, so we can get: 600g + ag500cm3 + acm3
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