Login/Sign Up
Home » A mass m is placed at P a distance h along the normal through the centre O of a thin circular ring of mass M and radius r. If the mass is removed further away such that OP becomes 2h, by what factor the force of gravitation will decrease, if h = r?
A mass m is placed at P a distance h along the normal through the centre O of a thin circular ring of mass M and radius r. If the mass is removed further away such that OP becomes 2h, by what factor the force of gravitation will decrease, if h = r?
CBSE | Class 11 | Gravitation | NCERT Exemplar | Physics
A mass m is placed at P a distance h along the normal through the centre O of a thin circular ring of mass M and radius r. If the mass is removed further away such that OP becomes 2h, by what factor the force of gravitation will decrease, if h = r?

Solution:

Let the radius of the ring be r
Let the mass of the ring be m
When small element dM is considered as the mass, the gravitation force becomes,

dF=\frac{G(dM)m}{x^{2}}

where x^{2}=r^{2}+h^{2}

The distance between m and the ring becomes 2h when the force is integrated.

i

More Material