Two bodies of masses `m_1` and `m_2` initially at rest at infinite distance apart move towards each other under gravitational force of attraction. Their relative velocity of approach when they are separated by a distance r is (G= universal gravitational constant.)

Options

A. `[2G(m_(1)-m_(2))/r]^(1//2)`
B. `[(2G)/r(m_(1)+m_(2))]^(1//2)`
C. `[r/(2G(m_(1)m_(2)))]^(1//2)`
D. `[(2G)/rm_(1)m_(2)]^(1//2)`

Answer

B