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: What is the specific gravity?

  1. Sep 15, 2010 #1
    1. A Cube of lengths 5cm each. The cube weighs .54kg. What is its specific weight?

    2. Answers: A)6 g cm3 B)3 g cm3 C) 2.5 g cm3 D) 2 g cm3

    3. 5x5x5 = 125cm3 540g/125= 4.32 g cm3 which is none of the above. Could someone verify that I'm correct before I make an idiot of myself when I challenge the question setter?
  2. jcsd
  3. Sep 15, 2010 #2
    I've found out by a process of deduction that the answer is supposed to be 2.5 gcm3.
    Is this wrong?
  4. Sep 15, 2010 #3


    User Avatar

    Staff: Mentor

    Specific gravity or specific weight?

    If sg - I would say your approach (giving 4.32) is correct. There are possible problems here, like sg being relative to something, not necessarily water - so it doesn't have to be identical to density.

    Answers given are strange, as units don't fit neither sg nor sw. Specific gravity should be unitles, specific weight units are N/m3 (more generally force/volume). g/cm3 is wrong - unless it is so called gram-force (9.8 mN) per cm3.
  5. Sep 15, 2010 #4
    In this case I believe it supposed to be water

    Thanks for the answer. It has confirmed my own conclusions...
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook