1. The problem statement, all variables and given/known data Fine grains of beach sand are assumed to be spheres of radius 38.1 micro meters (can't figure out the scientific sign). These grains are made of silicon dioxide which has a density of 2600 kilograms/meters^3. What is the mass in kg? 2. Relevant equations 3. The attempt at a solution I input 3 different answers and they're all wrong (603.2 kg and others near that - I know I'm way off). I'm not sure at all how to calculate. Please help!