試題詳解

5. A 1000 kg car traveling north at 15 m/s collides with a 2000 kg truck traveling east at 10 m/s. The two vehicles move away from the impact point as one. What is the velocity of the wreckage just after impact?
(A)0m/s
(B) 8.3 m/s
(C)5.0 m/s
(D) 6.6 m/s
(E) 1.7 m/s