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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 F1 and B presses the track with a force F2.
Options
F1 > F2
F1 < F2
F1 = F2
the information is insufficient to find the relation between F1 and F2.
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Solution
F1 > F2
Explanation:
Earth rotates 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" = ("m"("v" - omega"r")^2)/"r"`
`"N"_"A" = "mg" - ("m"("v" - omega"r")^2)/"r"`
Similary for Train `B : "N"_"A" = "mg" - ("m"("v" - omega"r")^2)/"r"`
Clearly `"N"_"B" < "N"_"A"` and F1 > F2.
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