COMEDK · Physics · 9. Gravitation
An uniform sphere of mass \(M\) and radius \(R\) exerts a force of \(F\) on a small mass \(m\) placed at a distance of 3R from the centre of the sphere. A spherical portion of diameter \(R\) is cut from the sphere as shown in the fig. The force of attraction between the remaining part of the disc and the mass \(\mathrm{m}\) is
- A F/3
- B 7F/12
- C 7F/9
- D 41F/50
Answer & Solution
Correct Answer
(D) 41F/50
Step-by-step Solution
Detailed explanation
The force exerted by the original sphere of mass \(M\) and radius \(R\) on a mass \(m\) at a distance \(d = 3R\) from its center is given by \(F = \dfrac{GMm}{(3R)^2} = \dfrac{GMm}{9R^2}\). The mass of the original sphere is \(M = \rho \times \dfrac{4}{3} \pi R^3\), where…
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