Multiple choice

Solid spheres of same material and same radius ‘a’ are touching each other. If the density is ‘D’, what is the gravitational force between them?

  1. (2/9)Gπ2D2a4

  2. (4/7)Gπ2D2a4

  3. (4/9) Gπ2D2a4

  4. (2/7) Gπ2D2a4

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

m, a m, a Here, F = G mm/(2a)2 = Gm2/4a4 = G/4a2 × (D × 4/3 × πa3)2 = (4/9)Gπ2D2a4