Insights Blog
-- Browse All Articles --
Physics Articles
Physics Tutorials
Physics Guides
Physics FAQ
Math Articles
Math Tutorials
Math Guides
Math FAQ
Education Articles
Education Guides
Bio/Chem Articles
Technology Guides
Computer Science Tutorials
Forums
Intro Physics Homework Help
Advanced Physics Homework Help
Precalculus Homework Help
Calculus Homework Help
Bio/Chem Homework Help
Engineering Homework Help
Trending
Featured Threads
Log in
Register
What's new
Search
Search
Search titles only
By:
Intro Physics Homework Help
Advanced Physics Homework Help
Precalculus Homework Help
Calculus Homework Help
Bio/Chem Homework Help
Engineering Homework Help
Menu
Log in
Register
Navigation
More options
Contact us
Close Menu
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Forums
Homework Help
Introductory Physics Homework Help
Finding downward force on immersed object
Reply to thread
Message
[QUOTE="kuruman, post: 6867288, member: 192687"] While you do this consider why you latched on the idea that the downward force exerted by the fluid is important. Here is what is going on. Let ##F_0## = force recorded with the mass hanging in air = ##mg=\rho_{\text{mass}}Vg.## ##F## = force recorded with the mass hanging under water = ##mg-B=\rho_{\text{mass}}Vg-\rho_{\text{water}}Vg.## Divide the bottom by the top equation, $$\frac{F}{F_0}=\frac{\rho_{\text{mass}}\cancel{Vg}-\rho_{\text{water}}\cancel{Vg}}{\rho_{\text{mass}}\cancel{Vg}}=1-\frac{\rho_{\text{water}}}{\rho_{\text{mass}}}.$$Then, $$\begin{align} & \frac{\rho_{\text{water}}}{\rho_{\text{mass}}}=1-\frac{F}{F_0} \nonumber \\ & \rho_{\text{mass}}=\rho_{\text{water}}\left(1-\frac{F}{F_0}\right)^{-1}. \nonumber\end{align}$$Note that the last equation is the formula that you used to calculate the entries under the heading "ρ(object) [kg/m^3] - using formula in above post", except that I used the symbol ##F## and you used the symbol ##F_i##. What these symbols stand for is the same force, namely the reading of the gauge with the object immersed. Your claim is baseless and shows that you lost track of what you set out to determine with this experiment. You need to find the unknown density of the masses in the net by measuring and recording (a) the force ##F_0## (or ##mg##) that they exert on the gauge when suspended in air and (b) the force ##F## (or ##F_i##) that they exert on the gauge when suspended under water. I will say no more on this thread because there is nothing left I can say. As someone remarked recently, "You can teach a hungry man how to fish and lead him to the water, but you can't make him fish." [/QUOTE]
Insert quotes…
Post reply
Forums
Homework Help
Introductory Physics Homework Help
Finding downward force on immersed object
Back
Top