the gravitational force between a point like mass M and an infinitely long,thin rod of linear mass density d at a perpandicular distance L from M is ??

							
Dear Prachi
Gravitational field at a distance r from the infinitely long rod with liner mass density d = 2Gd/r
here r=L and force will be field x mass
force= 2GMd/L
 
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AKASH GOYAL
AskiitiansExpert-IIT Delhi
 
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Gravitational Force is -Gm1m2 / r^2
since r is the radius and it is the prependicular distance between the rod and the point of mass M
the mass of the rod is d*V , since a rod is cylindrical the volume is pi*r*r*h and h = infinity
so mass of rod = d*infinity = infinity
Gravitational Force =  - G * infinity * M / L^2
                           =  -  infinity / l^2
since infinity divided by any positive number is also infinity
                           =  - infinity !
 
therefore gravitational force is - infinity
please approve if the answer is correct