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
Trending
Featured Threads
Log in
Register
What's new
Search
Search
Search titles only
By:
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
Physics
Classical Physics
Mechanics
Centripetal acceleration problem (box sitting on a table)
Reply to thread
Message
[QUOTE="etotheipi, post: 6470070"] You've got the right intuition, but let's iron a few things out. :biggrin: For a minute, forget about the Earth. Just imagine an idealised flat, rigid surface of infinite extent. Impose a uniform gravitational field ##-g \hat{\mathbf{y}}##. The book sitting on the table has its weight exactly canceled by the normal force exerted by the table, to satisfy the equilibrium condition. If the Earth wasn't rotating, that would be a pretty good local model. In fact, even though the Earth is rotating, the rate of rotation is sufficiently slow that this is an [I]approximately[/I] correct model. But we might want to think about a different, maybe more accurate, model in which the Earth has non-zero rotational speed. To simplify the description, imagine the table is at the equator. As you correctly deduced, the net force on the book must now be non-zero and pointing toward's the Earth's centre, in order to provide the necessary acceleration ##\rho \omega^2## toward the centre. In other words, the magnitude of the weight will slightly exceed the magnitude of the normal force. These two descriptions aren't in contradiction, simply because they're not describing the same scenario. The assumptions that underly the two models are different. :smile: [/QUOTE]
Insert quotes…
Post reply
Forums
Physics
Classical Physics
Mechanics
Centripetal acceleration problem (box sitting on a table)
Back
Top