When a person lifts a book while standing on the earth's surface. Why is his force considered external to the book-earth system? Isn't his force internal like the case of the forces that cause the exploson of a bomb. I think the forces the person exerts on both the book and the earth are internal since they are equal but opposite therefore resulting in the position of the centre of mass of the system being maintained and if i'm right is the mechanical energy of the system constant? Am i wrong? Please correct me.
Subscribe to:
Post Comments (Atom)
-
Why can't we use fissions products for electricity production ? As far has I know fissions products from current nuclear power plants cr...
-
I have searched for equations regarding craters and I came across two of them. The first one is from this NOAO website in the level two sec...
-
As the title says. It is common sense that sharp things cut, but how do they work at the atomical level? Answer For organic matter, such a...
-
How can we know the order of a Feynman diagram just from the pictorial representation? Is it the number of vertices divided by 2? For exampl...
-
Yesterday, I understood what it means to say that the moon is constantly falling (from a lecture by Richard Feynman ). In the picture below ...
-
Literature states neutral pion decay by QED cannot occur directly because the pion is uncharged. However, I cannot see why Photons are not a...
-
This image from NASA illustrates drag coefficients for several shapes: It is generally accepted that some variation of the teardrop/airfoil...
No comments:
Post a Comment