A brass washer has an outside diameter of 4.50cm with a hole of diameter 1.25 cm and is 1.50 mm thick. The density of brass is 8600 kg/m^3. If you put this washer on a laboratory balance, what will it weigh in grams.

Answer 1

To determine the weight of the brass washer, we need to calculate its volume and then multiply it by the density of brass.

First, let's calculate the volume of the washer. The washer can be seen as a cylinder with a smaller cylinder hole subtracted from it.

Volume of the outer cylinder = π r^2 h
= π (4.50 cm/2)^2 (0.0150 cm)
= 0.159 cm^3

Volume of the inner cylinder = π r^2 h
= π (1.25 cm/2)^2 (0.0150 cm)
= 0.018 cm^3

Volume of the washer = Volume of the outer cylinder - Volume of the inner cylinder
= 0.159 cm^3 - 0.018 cm^3
= 0.141 cm^3

Next, convert the volume from cubic centimeters to cubic meters:
0.141 cm^3 = 0.141 cm^3 × (1 m/100 cm)^3
= 0.141 × 10^-6 m^3

Now, we can calculate the weight of the brass washer:
Weight = Density × Volume
= 8600 kg/m^3 × 0.141 × 10^-6 m^3
= 1.2166 × 10^-3 kg

Finally, convert the weight from kilograms to grams:
Weight = 1.2166 × 10^-3 kg × 1000 g/kg
= 1.2166 g

Therefore, the brass washer will weigh approximately 1.2166 grams.