Two bodies of masses `m_1 and m_2` are initially at rest and infinite distance apart. Due to mutual attraction, they approach each other. When they are r distance apart, their relative velocity of approach is

Options

A. `[(2G(m_1+m_2))/r]^(1//2)`
B. `[sqrt((2G)/r)((m_1+m_2)/(2))]^(1//2)`
C. `[r/(2G(m_1*m_2))]^(1//2)`
D. `[(2G)/r*(m_1m_2)]^(1//2)`

Answer

A