1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Mass problems

  1. Feb 5, 2008 #1
    I am having trouble with how to set up the equation for this problem....

    Os is the densest element known. Given that the density of Os is 22.57g/cm^3, calculate the mass, in kg, of an Os sphere 15 cm in diameter, which is about the size of a grapefruit.

    Any help would be greatly appreciated. I am really confused with where the diameter fits in... I feel so lost in this class! Yikes!
  2. jcsd
  3. Feb 5, 2008 #2


    User Avatar
    Gold Member

    You need to work on the basics:
    Volume of a sphere = 4/3( pi ) (radius cubed)
    Density = mass/volume
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook