Finding liquid density from neutral buoyancy of a sphere

[talaroue]

Homework Statement

A 7.56 cm diameter sphere with a mass of 137.1 g is neutrally buoyant in a liquid. What is the density of the liquid?

Homework Equations

B-mg=0
B=V*density*g

The Attempt at a Solution

B=mg
V*density*g=mg
denisty=M/V
denisty= .1371 kg/(4/3*PI*r^2) because its a sphere

What am I doing wrong?

 

[talaroue]

any ideas? It seems easy but it is not turning out correct.

 

[Doc Al]

B=mg
V*density*g=mg
denisty=M/V
denisty= .1371 kg/(4/3*PI*r^2) because its a sphere

Double-check that volume formula.

 

[talaroue]

ahhhh! i was getting frustrated because we still can figured what i was doing wrong on this one...


https://www.physicsforums.com/showthread.php?t=319168"