Alphonse moves eastward in a car at 30 m/s. Velma, moving eastward in a train at 70 m/s, passes him. Alphonse's velocity relative to Velma is
A) 100 m/s eastward.
B) 30 m/s westward.
C) 40 m/s eastward.
D) 40 m/s westward.
E) 100 m/s westward.

Question

Quizplus · Accepted Answer

Alphonse's velocity relative to Velma is the difference in their velocities: 30 m/s - 70 m/s = -40 m/s, which means 40 m/s westward.

Alphonse Moves Eastward in a Car at 30 M/s