Chemistry Question - Need Help

[Robert01]

Hi all I'm having a bit of a problem with a problem from my college chemistry assignment, here it is:

A cylindrical rod formed from silicon is 16.8 cm in length and has a mass of 2.17 kg. The density of silicon is 2.33 g/cm^3. What is the diameter of the cylinder? (Recall that the volume of a cylinder is given by pie*r^2*h.

I would appreciate a brief explanation also, not just the answer. Thanks.

 

[PsychoAndy]

Aw man, i did this kinda problem in Geometry, i think...lemme think...

Edit: NM, i'll let you do the thinking

 

[Wallydraigle]

Seems pretty straight forward. Good luck figuring it out

 

[rmblam]

Hint: Density = mass/volume

you have the mass and the density. solve for volume.

Use the volume to solve for r in v=pi x r^2 x h


r = 4.2 and the diameter is 8.4

 

[OS]

Mass = Density x Volume

Convert the given 2.17 kg to 2170 g, use the given equation for the cylinder, use the given value for density of silicon, plug everything into the above equation and solve by basic algebra.

 

[warlord]

I hope you just need chemistry to meet some graduation because this problem is not very difficult.

what is your major anyhow?

 

[morkinva]

ya doesn't seem to be a chemistry question at all.

heres my guess: 4.2 cm

V= pi*r^2*h = [pi*r^2(16.8cm)]
V*D = mass
[pi*r^2(16.8cm)][2.33 g/cm^3] = 2170 g
r^2 = 17.64595 cm^2
r = 4.2 cm
d = 8.4 cm

edit>>> durr
edit>>> double durr