Question

a rolling white ball strikes a stationary black ball. if the white ball continues 1 point to move in the same direction after it strikes the black ball, which best describes the black balls momentum just after the collision? the black balls momentum just after the collision is equal to the white balls momentum just before the collision. the black balls speed after the collision is less than the white balls initial speed, but direction cannot be determined. the black balls momentum just after the collision is less than the white balls initial momentum. both balls are moving in the same direction after the collision nothing can be determined regarding the black balls momentum just after the collision. there is too little information.

Explanation:

According to the law of conservation of momentum, \(p_{initial}=p_{final}\). Let the mass of the white ball be \(m_w\), its initial velocity be \(v_{w,i}\), its final velocity be \(v_{w,f}\), and the mass of the black ball be \(m_b\) and its final velocity be \(v_{b,f}\). Then \(m_wv_{w,i}=m_wv_{w,f}+m_bv_{b,f}\). Since \(v_{w,f}> 0\) (moves in the same direction), \(m_bv_{b,f}=m_w(v_{w,i} - v_{w,f})\). So \(m_bv_{b,f}

Answer:

The black ball’s momentum just after the collision is less than the white ball’s initial momentum. Both balls are moving in the same direction after the collision.