What is the diameter of this cylinder?

Question

A cylindrical rod formed from silicon is 16.9 cm in length and has a mass of 2.10 kg. The density of silicon is 2.33 g/cm3. What is the diameter of the cylinder? (Recall that the volume of a cylinder is given by πr2h, where r is the radius, and h is its length.)

aghh D; thank you for anyway that tried

Answer 1

Convert kg --> g, so 2.10kg = 2100g

Divide the mass by the density to get the volume (in cm³ and notice that units of g cancel out), so

V = 2100/2.33 = 901.2875536

V = πr²h

901.2875536 = π(r²)(16.9)

Solve for r, which should be ~4.12cm

Since diameter is twice the length of the radius, d = ~8.24cm

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