Apparent mass (specific gravity)

[knowak87]

Homework Statement

A piece of cork having a mass of 25 grams in air and a specific gravity of 0.25 is attached to a lead sinker whose mass is 266 grams in air. What will be the apparent mass of the two solids when they are both immersed in water?

Homework Equations

The Attempt at a Solution

 

[ideasrule]

To start out, draw a free-body diagram; it might be helpful to consider the sinker+cork as one object. Identify all forces and write out Newton's second law.