Question

Two lead balls of masses m and 5m having radii R and 2R are separated by 12R, If they attract.each other by gravitational force, the distance covered by small sphere before they touch each other is

• A. 10 R
• B. 7.5 R
• C. 9 R
• D. 2.5 R

Answer 1

Answer: (B)

7.5 R

Answer 2

Effective distance =9R Distance travelled by Smaller mass= x $x = \left(\frac{m_2}{m_1 + m_2 }\right) (9R)$