A scale reads 20.3 N when an object is not submerged in water and 20.0 N when the object is (completely) submerged in water.

What is the specific gravity of the object?

well, it has .3N of bouyancy.

that is equivalent to what volume of water?

.3=densitywater*g*volume
solve for volume

then density= weight/volume=20.3/volume

and specfic gravity= denstiy/denstiywater.

What is the volume , in L occupied by 50.0 kg ethanol at 20 degree centimeter ? the density of ethanol at 20 degree centimeter is 0.789 g/ml ?

To find the specific gravity of the object, we need to understand its definition. Specific gravity is the ratio of the density of a substance to the density of a reference substance. In this case, the object is submerged in water, so we'll use water as the reference substance.

To solve this question, we need to know two formulas. The first is Archimedes' principle, which states that the buoyant force on an object submerged in a fluid is equal to the weight of the fluid displaced by the object. Mathematically, we can express this as:

Buoyant force = weight of fluid displaced

The second formula is the definition of specific gravity:

Specific gravity = density of substance / density of reference substance

Now let's go through each step to find the specific gravity:

Step 1: Calculate the weight of the fluid displaced when the object is submerged. The difference in scale readings (20.0 N - 20.3 N) represents the buoyant force acting on the object. So, the weight of the fluid displaced is 20.3 N - 20.0 N = 0.3 N.

Step 2: Determine the weight of the displaced fluid. Since the buoyant force is equal to the weight of the fluid displaced, the weight of the displaced fluid is 0.3 N.

Step 3: Calculate the density of the object. The density of the object can be determined using the equation: density = mass / volume. However, we don't have the mass or volume of the object, so we'll use the fact that the weight of the object (when not submerged) is 20.3 N. Weight is given by the equation: weight = mass × gravitational acceleration. Therefore, we can rewrite this equation as: mass = weight / gravitational acceleration. Assuming the gravitational acceleration is approximately 9.8 m/s², the mass of the object is 20.3 N / 9.8 m/s² = 2.07 kg.

Step 4: Calculate the density of the object. Since density is given by the equation density = mass / volume, and we know the mass of the object (2.07 kg), we need to find the volume. The volume of the object can be determined by dividing the weight of the displaced fluid by the density of the reference substance (water in this case). Therefore, the volume of the object is 0.3 N / (9.8 m/s² × density of water). The density of water is approximately 1000 kg/m³, so the volume of the object is 0.3 N / (9.8 m/s² × 1000 kg/m³) = 0.0000306 m³.

Step 5: Calculate the density of the reference substance (water). The density of water is approximately 1000 kg/m³.

Step 6: Determine the specific gravity. Using the formula specific gravity = density of substance / density of reference substance, we can calculate the specific gravity as: specific gravity = (mass/volume of object) / (density of water). Plugging in the values, specific gravity = (2.07 kg / 0.0000306 m³) / 1000 kg/m³ ≈ 67.6.

Therefore, the specific gravity of the object is approximately 67.6.