What am I doing wrong?: Buoyancy of an Object Homework Question

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To determine the density of a neutrally buoyant sphere with a diameter of 7.56 cm and mass of 137.1 g, the relevant equations include buoyancy (B) and density (density = mass/volume). The user attempted to calculate density using the formula density = mass/volume, but mistakenly applied the volume formula for a sphere. The correct volume formula is V = (4/3)πr^3, not (4/3)πr^2. The discussion highlights the importance of correctly applying formulas in physics problems, particularly in buoyancy calculations. Clarifying the volume formula is essential for solving the problem accurately.
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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?
 
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any ideas? It seems easy but it is not turning out correct.
 
talaroue said:
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.
 

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