# A solid sphere of uniform density and radius applies a gravitational force of attraction equal to on a particle placed at , distance from the centre of the sphere. A spherical cavity of radius is now made in the sphere as shown in figure. The sphere with cavity now applied an gravitational force on same particle placed at . The ratio will be a) 1/2 b) 7/ 9 c) 3 d) 7

## Question ID - 55345 :- A solid sphere of uniform density and radius applies a gravitational force of attraction equal to on a particle placed at , distance from the centre of the sphere. A spherical cavity of radius is now made in the sphere as shown in figure. The sphere with cavity now applied an gravitational force on same particle placed at . The ratio will be a) 1/2 b) 7/ 9 c) 3 d) 7

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(b)

Gravitational force due to solid sphere, where and are mass of the solid sphere and particle respectively and is the radius of the sphere. The gravitational force on particle due to sphere with cavity = force due to solid sphere creating cavity, assumed to be present above at that position So, Next Question :
 The escape velocity of a body from earth’s surface is . The escape velocity of the same body from a height equal to from earth’s surface will be a) b) c) d)  