Question

Let ρAl represent the density of aluminum and ρFe that of iron. Find the radius of a solid aluminum sphere that balances a solid iron sphere of radius rFe on an equal-arm balance. (Use any variable or symbol stated above as necessary.)

Answer 1

mass of Fe=
\[\rho Fe*(4/3)\pi (rFe)^3\]
this should be equal to the mass of Al
mass of Al=
\[\rho Al *(4/3)\pi (rAl)^3\]
equate them and solve for rAl