• anonymous
A Log floats in a river with one-forth of its volume about the water. (a) what is the density of the log?
  • Stacey Warren - Expert
Hey! We 've verified this expert answer for you, click below to unlock the details :)
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
  • chestercat
I got my questions answered at in under 10 minutes. Go to now for free help!
  • TuringTest
if one-fourth of the volume is above water then I think the density is 25% less than that of water I never took any fluid mechanics though, so I'm not sure... you say about though, so I'm not sure the meaning of your question
  • anonymous
So summing up the forces, \[ mg = \rho_w V_s g\] where rho_w is the density of water and V_s is the volume of the log that's submerged. Rewriting the left side, \[\rho_lV_t g = \rho_wV_sg\] where rho_l is the density of the log and V_t is the total volume of the log. Cancelling g and manipulating, we find that \[\frac{\rho_l}{\rho_w} = \frac{V_s}{V_t} = \frac{3}{4} \] so \[\rho_l = \frac{3}{4} \rho_w \] and indeed, as Turing said, the density of the log is 3/4 the density of the water.
  • anonymous
This is of course neglecting things like surface tension which are very important but I suspect are not being taken into account here :)

Looking for something else?

Not the answer you are looking for? Search for more explanations.