# Buoyant force of an aluminum block

1. Apr 17, 2012

### domyy

1. The problem statement, all variables and given/known data

An aluminum block has a mass of 0.25kg and a density of 2700 kg/m cubic.

a) calculate the volume of the aluminum block.
b) Determine the buoyant force exerted on this block when it´s completely submerged in water of density 1000kg/m cubic.

2. Relevant equations

v = m/d

3. The attempt at a solution

I already solved for a and I got:

v = 0.25/2700 = 9.25 x 10 to the power of -5

Now for b), I am not sure... i did something like:

9.25 x 10-5 x 1000 x 10
9.25 x 10-5 x 1.0 to the power of 3 x 10
9.25 x 10-1 ?

Last edited: Apr 17, 2012
2. Apr 17, 2012

### Staff: Mentor

OK. (But don't leave out the units.)

If the block were submerged in water, that would be about right. (Using g = 10 m/s2.) (Again, don't leave out the units.)

3. Apr 17, 2012

### domyy

Why do i have someone saying the answer should be 92.5 for a) ?

Last edited: Apr 17, 2012
4. Apr 18, 2012

### Staff: Mentor

They are expressing the volume in cm3 instead of m3.

Last edited: Apr 18, 2012