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**1. Homework Statement**

An iron anchor of density 7870 kg/m3 appears 290 N lighter in water than in air.

What is the volume of the anchor?

**2. Homework Equations**

Fnet = 0 (we are doing static fluids) = forces up - forces down

Fbuoyant = density of liquid*g*volume of object

density = mass/ volume, so mass = density*volume

Weight in the air = mg, so weight in the water = (mg - 290N)

density of water = 1000 kg/m^3

**3. The Attempt at a Solution**

Fnet = Fbuoyant - (mg - 290N)

0 = 1000 * g * volume - (7870* 9.8*volume - 290N)

-290N = 9800 * volume - 77126 * volume

factor out volume, and

-290/ -67326 = volume = .00431 m^3

(the units work out right, I just left them out here to try to make things clearer)

unfortunately this answer is wrong....

any help would be great!

thanks