Question

A cylinder rod formed from silicon is 46.0 cm long and has a mass of 3.00 kg. The density of silicon is 2.33 g/cm^3. What is the diameter of the cylinder? (the volume of cylinder is given by (pi)r^2h, where r is the radius and h is the length)

Answer 1

Answer:

I make it 6 cm diameter (well....5.97 cm really, but it depends how many places you take π to!).

Explanation:

You have been given density (d) and mass (m), so first you can determine volume (v).

d=m/v therefore v=m/d = 3000/2.33 = 1287.55 cm^3

Now you have the volume and the length (L) from which you can work out the cross sectional area, π.r2, and from that the diameter.
Volume v =π.r2.L therefore r = √v/π.L and diameter D = 2r = √(vπ.L)x 2.

So plugging in the numbers gives: D = √(1287.55/3.142X46) X2 = 5.97 cm.