1
Question
A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,
A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,
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Solution
The correct options are
A The gravitational force due to this object at the origin is zero
B The gravitational force at the point B (2, 0, 0) is zero
C
Since cavities are symmetrical w.r.t. O. So the gravitational force at the centre is zero.
The radius of the circle x2+y2=36 is 6.
For all points for r≥6, the body behaves as if whole of the mass is concentrated at the centre. So the gravitational potential is same.
Above is true for x2+y2=4 as well.
A
The gravitational force due to this object at the origin is zero
B
The gravitational force at the point B (2, 0, 0) is zero
C
Since cavities are symmetrical w.r.t. O. So the gravitational force at the centre is zero.
The radius of the circle x2+y2=36 is 6.
For all points for r≥6, the body behaves as if whole of the mass is concentrated at the centre. So the gravitational potential is same.
Above is true for x2+y2=4 as well.