Finding the desnity of a cylinder.

Question

If a cylinder has a mass of 18.426g, a diameter of 1.34cm, and a height of 6.48cm, what is the density of the cylinder?

Answer 1

Density is how much mass is in a given volume (ρ = m / v).

The mass of the object is given, 18.426 g.

The next thing we need to do is find the volume of the cylinder. V = π * (d / 2)² * h

So if we plug everything in, we get: V = (3.14159) * (1.34 / 2)² * 6.48 = 9.138 cm³

Then, we plug our mass and volume into this formula: ρ = m / v

Once we plug everything in, we get: ρ = (18.426 / 9.138) = 2.02 g/cm³

Density = 2.02 g/cm³

Answer 2

Density if the mass divided by the volume. The volume of a cylinder is the area of the base (which is a circle so it is πr²) times the height. In this case, we have been given the diameter so we need to divide it by 2 to get the radius (r). So, if the diameter is 1.34, then the radius is 1.34/2 = 0.67 cm then we would calculate the volume like this:

V = πr²•h

V = π(0.67)²•(6.48)

V = 9.138490905 cm³

The density then calculated like this:

D = M/V

D = (18.426 g)/(9.138490905 cm³)

D = 2.016306652 g/cm³ however, we need to round to the appropriate significant figure. The smallest sig fig of numbers given is 3 (both 1.34 cm and 6.48 cm have 3 sig figs) so our answer should have 3 sig figs.

So D = 2.02 g/cm³