Two model railway carriages, P P\,P and QQQ, are on a smooth, straight, horizontal track, as shown in the diagram below. Carriage P P\,P of mass 2.0 kg is travelling to the right with a velocity of 5.0 m s-1. Carriage Q Q\,Q of mass 3.0 kg is travelling to the left with a velocity of 2.0 m s-1.
During the collision, the magnitude of the impulse exerted on carriage P P\,P by carriage Q Q\,Q is 12 N s.
Taking the direction of PPP's initial motion as the positive direction, which of the following pairs correctly identifies the velocity of carriage PPP (vPv_PvP) and the velocity of carriage QQQ (vQv_QvQ) immediately after the collision?
vP=−1 m s−1,vQ=2 m s−1v_P = -1\text{ m s}^{-1},\quad v_Q = 2\text{ m s}^{-1}vP=−1 m s−1,vQ=2 m s−1
vP=11 m s−1,vQ=−6 m s−1v_P = 11\text{ m s}^{-1},\quad v_Q = -6\text{ m s}^{-1}vP=11 m s−1,vQ=−6 m s−1
vP=−1 m s−1,vQ=6 m s−1v_P = -1\text{ m s}^{-1},\quad v_Q = 6\text{ m s}^{-1}vP=−1 m s−1,vQ=6 m s−1
vP=−1 m s−1,vQ=−6 m s−1v_P = -1\text{ m s}^{-1},\quad v_Q = -6\text{ m s}^{-1}vP=−1 m s−1,vQ=−6 m s−1