Displacement and Density

[sharonita]

Heres the question:
A 6.8-kg piece of metal displaces 1 liter of water when submerged. Calculate its density.

So I have no idea where to begin or how the displacement relates to the density. What can you suggest? Thanks!

[sharonita]

i reallllyy need help =\
anybody?

[Erwin Schrodinger]

Density equals mass divided by volume. If the object displaces 1 liter of water, then it has a volume of 1 liter. You also have to know that 1 liter = 0.001 cubic meters. The objects density is 6.8kg/0.001m^3 or 6800kg/m^3.

[sharonita]

But wasnt the weight 6.8kg?

[Erwin Schrodinger]

Yes the mass is 6.8kg and the volume is 1liter which is equal to 0.001m^3. The density is mass divided by volume which is 6.8kg/0.001m^3. Do 6.8 divided by 0.001 on a calculator; what answer do you get?

[cepheid]

But wasnt the weight 6.8kg?


Nope, the mass was 6.8 kg. The kilogram is a unit of mass, not weight.

[sharonita]

6800...thanks!

[sharonita]

ohhhh. okay thanks a bunch!
im such a newbie, thats all. :)