The density of lead is 11.34g/cm^3 and the density of aluminum is 2.69 g/cm^3. Find the radius of lead and aluminum spheres each having a mass of 60kg

Question

I have 

11.34=60/v=680.4

2.69=60/v=161.4

then 680.4=(4/3)3.14v^3

and 161.4=(4/3)3.14v^3

it says I keep getting the wrong answer. Do I need to convert the kg to g for the density equation? Where am I going wrong?

Answer 1

You do need to convert  60kg to grams since your density unit has grams. Also it seems you are using "v" for volume at first, but then you have "v" in the place of radius for the sphere!

I would suggest dividing mass (60,000g) by each density to find the volume of each ball. Then solve for each radius (r) from the spherical volume formula. V = (4π/3) r³

I got 10.81cm for lead and 17.46 cm for aluminum.