1. The problem statement, all variables and given/known data Two spheres are cut from a certain uniform rock. One has a radius 4.50cm. The mass of the other is 5 times greater. Find its radius 2. Relevant equations r1 = 4.50cm r2 = ? when mass is 5x greater 3. The attempt at a solution Looking at this problem I first thought of somehow integrating the volume of a sphere which is 4/3[tex]\pi[/tex]r3. But then i though i was just thinking too hard. it made more sense for the radius to be 5x the radius as i figure the mass was proportional to the radius. so: r2 = 5(4.50cm) = 22.5cm however i got this marked wrong as the answer was 7.69 cm. what wasn't I looking at clearly?