Collision between spheres

• Given 2 spheres \((p_1,v_1,r_1,m_1)\), \((p_2,v_2,r_2,m_2)\).
• Collision when \( \|p_1-p_2\| \leq r_1+r_2\)

• What happen with their velocities ?
• • \(v_1\to v_1^{new}\), \(v_2\to v_2^{new}\)