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 ??

420 Points
13 years ago

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

All the best.

AKASH GOYAL

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Sudheesh Singanamalla
114 Points
13 years ago

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

Shaikh Jinnatul
13 Points
2 years ago
There will be no change in the force onM due to another mass ,
Therefore , total mass = F+2F
=3F
Therefore , the forces are F,2F.