Concepts Of Physics MCQ Edition [Volume 1]PhysicsCircular Motion
Along the equator, a train A travels from east to west while a second train B of identical mass travels from west to east at an equal speed. Train A exerts a force F₁ on the track, whereas train B exerts a force F₂ on the track.
Options
- AF₁ = F₂
- BThe given information is insufficient to establish a relation between F₁ and F₂
- CF₁ > F₂
- DF₁ < F₂
Correct answer
C. F₁ > F₂
Step-by-step solution
Let v be the speed of the trains relative to the Earth, be the angular velocity of the Earth, and R be the radius of the Earth. The Earth rotates from west to east. The absolute speed of a point on the equator is R from west to east. Train A travels from east to west. Its absolute speed is v_A = R - v . Train B travels from west to east. Its absolute speed is v_B = R + v . The normal force N exerted by the track on the train provides the necessary centripetal force along with gravity. The equation of motion is mg -