Two trains move on parallel straight tracks in the same direction

PHYSICS · Subjective · CBSE · Physics · Motion in a Plane · Motion in a Plane

Problem

Two trains move on parallel straight tracks in the same direction. Train P travels at

72\,\text{km}\,\text{h}^{-1}

while train Q travels at

54\,\text{km}\,\text{h}^{-1}

. Calculate the velocity of train P as observed from train Q.