Two carts collide and stick together. Cart 1 has mass 4 kg moving at 6 m/s. Cart 2 has mass 2 kg moving at 3 m/s in the OPPOSITE direction. What is the combined velocity after the collision?
A5.0 m/s (in Cart 1's original direction)
B3.0 m/s (in Cart 1's original direction)
C4.5 m/s (in Cart 2's original direction)
D0 m/s (both stop)
Explanation
📌 Total initial momentum: (4)(+6) + (2)(−3) = 24 − 6 = 18 kg·m/s. After collision: (4+2)v = 18 → v = 3.0 m/s in Cart 1's (positive) direction. Distractor A ignored the opposing sign of Cart 2; C mixed the ratio; D would only occur if momenta were exactly equal and opposite, not the case here.