Question

You are walking toward the back of a train that is moving forward with a constant velocity. The train's velocity relative to the ground is 30 m/s forward. Your velocity relative to the train is 1.5 m/s backward. How fast are you moving relative to the ground?

Answer 1

28.5 m/s forward

Consider the train as a “positive movement” and you as a “negative movement” combine those and take the larger direction

Answer 2

28.5 m/s

Step-by-step explanation:

There are 2 different velocities: the train velocity and yours velocity. They're in opposite directions, so one is positive and other is negative. Take the forward direction as the positive:

V = +30 -1.5

V = 28.5 m/s