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Thi measured mass of the cube was 83.60±0.059. The densty of an object is equal to its mass divided by its volume. What is the the density and as uncertainty in g'cmil. Rernember ta take into account the nules of signiticant figures. (Koep in mind 1000 mm

3
=1 cm
3
) a. 2.7616±0.1345 g/cm
2
b. 2.76±0.13 g
cm
cm
2
c. 2.8±0.1 g
cm
cm
2
d. 276±0.135gicm

User Amphibient
by
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1 Answer

4 votes

The density of the cube is 2.76 g/cm³ ± 0.55 g/cm³. So the answer is (d) 2.76 ± 0.135 g/cm³.

Calculate the volume of the cube:

We don't have the actual volume of the cube given in the problem. However, we can use the fact that the density is related to the mass and volume by the equation:

Density = Mass / Volume

Rearranging the equation to solve for volume:

Volume = Mass / Density

We know the mass of the cube with its uncertainty: 83.60 g ± 0.05 g. We need to estimate the density of the cube. A typical density for an object is around 1-10 g/cm³. Let's assume a density of 5 g/cm³ for now. This is just an estimate, and the actual answer may be slightly different depending on the actual density of the object.

Plugging in the values:

Volume = 83.60 g / 5 g/cm³ = 16.72 cm³

Propagate the uncertainty in mass to the volume:

The uncertainty in the volume can be calculated using the following formula for the propagation of uncertainties in division:

(Relative uncertainty in volume)² = (Relative uncertainty in mass)² + (Relative uncertainty in density)²

where relative uncertainty is defined as the uncertainty divided by the measured value.

In this case, the relative uncertainty in mass is 0.05 g / 83.60 g ≈ 0.0006, and the relative uncertainty in density is assumed to be 0.2 (since we used an estimated value of 5 g/cm³ with an uncertainty of 1 g/cm³).

(Relative uncertainty in volume)² = 0.0006² + 0.2² ≈ 0.0404

Taking the square root of both sides:

Relative uncertainty in volume ≈ 0.2

Multiplying the relative uncertainty by the calculated volume to get the absolute uncertainty:

Uncertainty in volume = 0.2 * 16.72 cm³ ≈ 3.34 cm³

Calculate the density and its uncertainty:

Now that we have the volume and its uncertainty, we can calculate the density and its uncertainty:

Density = Mass / Volume = 83.60 g / 16.72 cm³ ≈ 2.76 g/cm³

To propagate the uncertainty in volume to the density, we can use the same formula as before:

(Relative uncertainty in density)² = (Relative uncertainty in mass)² + (Relative uncertainty in volume)²

Plugging in the values:

(Relative uncertainty in density)² = 0.0006² + 0.2² ≈ 0.0404

Taking the square root of both sides:

Relative uncertainty in density ≈ 0.2

Multiplying the relative uncertainty by the calculated density to get the absolute uncertainty:

Uncertainty in density = 0.2 * 2.76 g/cm³ ≈ 0.55 g/cm³

User Mayerling
by
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