Problem 8-34 Elastic collision - B

A superball of mass \(22\; g\) rolls with a speed of \(3.5\; m/s\) toward another (stationary) superball of mass \(27\; g\). If the balls have a head-on elastic collision, what are the velocities magnitudes and directions) of the balls after the collision?
[Ans. \(3.1\; m/s\) forward and \(0.4\; m/s\) backward]

Accumulated Solution

Diagram of ball.


If any unknown velocity is actually negative a minus sign will appear in the solution.

In terms of \(m_1\), \(m_2\), \(v{_1}'\) and \(v{_2}'\) what is the expression for the conservation of momentum according to the choice in the drawing (B)?


(A)   \(m_1\; v_1 = m_1\; v{_1}'+ m_2\; v{_2}'\)

(B)   \(m_1\; v_1 = -m_1\; v{_1}'+ m_2\; v{_2}'\)

(C)   \(m_1\; v_1 = m_1\; v{_1}'- m_2\; v{_2}'\)