## Question:

A train is moving at a constant speed ${ \upsilon }_{ t }$ relative to the ground, when a person who initially at rest (relative to the train) starts running and gains a speed ${ \upsilon }_{ 0 }$ (relative to the train) after a time interval $\triangle t$. Had the person started from rest on the ground (as opposed to the moving train), would the magnitude of the total impulse exerted on the person during $\triangle t$ be smaller than, equal to, or larger than the impulse needed to cause the same change in relative velocity in the same amount of time on the moving train? Assume that the person always moves in the direction of motion of the train.