Question

A factory produces weighted balls to use for exercise, by filling spherical rubber shells of different sizes with a sand-like material. The material's density is 1.51 grams per cubic centimeter. Assuming the shell weighs 10 grams, what should be the ball's radius so, when full, it weighs 1 kilogram (or 1000 grams)?

Answer 1

Answer:

Step-by-step explanation:

1000 g = weight of sand + 10 g

=> weight of sand = 990 g

=> vol of sand * density = 990 g

=> vol of sand = 990/density

=> vol of sand = 990/1.51

=> vol of sand = 655.6291391

=> vol of sand = 4/3 pi * r^3 = 655.6291391

=> r^3 = 156.5199

=> r = 5.389 cm