Initially, I was looking for how centripetal force is produced on the surface of the rotating earth for a mass kept at any latitude. I went through the following threads -
- Which force provides the centripetal acceleration that makes objects on earth's surface rotate about Earth's axis of rotation?
- Is the normal force equal to weight if we take the rotation of Earth into account?
- Question about the Normal Force exerted by Planet Earth in relation to centripetal force
- If the ground's normal force cancels gravity, how does a person keep rotating with the Earth?
From there, I understood that the resultant of normal force (N) and gravity (mg) is the required centripetal force. But what is bothering me now is HOW? According to the answers, the normal force is slanted such that it is not exactly opposite to gravity. Thus, they don't cancel out, resulting in a horizontal centripetal force. I'm still confused and have the following questions :
Why is normal force slanted in the first place ? (Is it because of the earth's bulge, friction or centrifugal force?)
I think there's also a vertically-upwards component of the resultant, why is that? (the resultant of normal force and gravity)
Source of the image - https://en.wikipedia.org/wiki/Equatorial_bulge
Edit - I've gone through this question Is the normal force equal to weight if we take the rotation of Earth into account? but this doesn't clear my doubt regarding the upward component of the resultant of gravity and the normal force. I posted this question because I wanted some more insight into that poleward force and its relation to the bulge of the earth, which isn't emphasised in that question. kindly reopen my question.