A train is moving slowly on a straightly track with a constant speed of `2 ms^(-1)` . A passenger in the train starts walking at a steady speed of `2 ms^(-1)` to the back of the train in the opposite direction of the motion of the train . So, to an observer standing on the platform directly in the front of that passenger appears to be

Options

A. `4ms^(-1)`
B. `2ms^(-1)`
C. `2ms^(-1)` in the opposite direction of the train
D. zero

Answer

D

Explanation

Velocity of passenger w.r.t. combine system (train + passenger) is zero.