Question

A train A runs from east to west and another train $B$ of the same mass runs from west to east at the same speed along the equator. A presses the track with a force $F_{1}$ and $B$ presses the track with a force $F_{2}$

• A. $F_{1}>\, F_{2}$
• B. $F_{1}<\,F_{2}$
• C. $F_{1} = F_{2}$
• D. The information is insufficient to find the relation between $F_{1}$ and $F_{2}$

Answer 1

Answer: (A)

Earth rotate about its axis from west to east
For Train A : $V_{A}=V- \omega r$
For Train B : $V_{B}=V+\omega r$
For Train A
$ mg-N_{A}=\frac{m \left(v-\omega r\right)^{2}}{r}$

$N_{A}=mg-\frac{m\left(v-\omega r\right)^{2}}{r}$
Similarly for Train B: $N_{B}=mg-\frac{m\left(v+\omega r\right)^{2}}{r}$
Clearly $N_{B}<\,N_{A}$ and
$F_{1}>\, F_{2}$