TY  - BOOK
AU  - Fábio M. S. Lima 
TI  -  Where Exactly Is the Weight of a Body Applied?: (Journal Article)
T2  -  American Association of Physics Teachers ,American Institute of Physics, Volume 61, Number 5
SN  - 0031-921X
U1  - 530.071 
PY  - 2023///
CY  - Washington , DC
PB  - American Association of Physics Teachers
KW  - Newtonian mechanics,
KW  - Gravitational force
KW  - Textbooks
N1  - ***______{For Hard Copy, Please visit Library.}________***
N2  - Abstract-

A common belief among undergraduates is that the gravitational force exerted by a homogeneous sphere of mass M on an extended body of mass m with arbitrary shape is always given by Newton’s law of gravity F = GMm/rcc2, where rcc is the distance from the center of the sphere to the center of mass (c.m.) of the body. In this note, I introduce the simplest counterexample of a vertical dumbbell to show that, in general, this procedure does not return the correct gravitational force. I also show that not even the center of gravity (c.g.) of the body, determined according to the weighted-average formulae found in textbooks, leads to the correct force. Finally, I present an equation for the c.g. position whose solution always corresponds to the correct force.


UR  - https://doi.org/10.1119/5.0060495
ER  -