Question

a ball with a r of 2inches weighs 2.40 lb.find the weight of a ball of the same material with 3 inches r

Answer 1

Weight and volume are proportional to r^3. Multiply the weight of the smaller ball by (3/2)^3 , which is 27/8 = 3.375.
2.40 lb x 3.375 = ____ lb