How do i compute for the volume if the density of ore is not given?

[raisatantuico]

Homework Statement

An ore sample weights 17.50 N in air. When th sample is suspended by a light cord and totally immersed in water, the tension in the cord is 11.20 N. What is the total volume of the object?

Homework Equations

B = rho * volume displaced* g

B= weight in air - weight apparent

The Attempt at a Solution

I took the tension in the string as equal to the apparent weight. So using that I computed for the buoyancy: 17.50N - 11.20N = 6.3N

So, 6.3N = rho*volume of water displaced *g

how do i compute for the volume if the density of ore is not given?

 

[JaredJames]

Volume of water displaced = volume of ore

You know the density of water so how about calculating the volume of water displaced?

Jared

 

[raisatantuico]

So, is it just 6.3N/(9.8*1000kg/m^3) = 6.43x10^-4 m^3

 

[JaredJames]

F_buoyant = density * volume * gravity

Rearranging gives F_buoyant / (density * gravity) = volume

6.3 / (9.8 * 1000) = 6.43x10^-4 m^3

Jared