TBR Centripetal Force = Smaller Normal Force???

[justadream]

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TBR Physics book 1 page 252 #4

The question is about explaining the variation of "g" on Earth. Answer is "differing centrifugal forces at the [differing] locations".

The answer key for the question says "a bigger centripetal force inwards means a bigger centrifugal force outwards. This lessens the normal force with the Earth and makes you fee lighter"

I thought a bigger centripetal force is associated with a bigger normal force? Can someone clarify this?

 

[tdod]

would help if u posted the entire question.

at any rate, the important thing to keep in mind is that neither the centripital force nor the centrifugal forces are real forces. for instance, when the earth orbits the sun, there is no centripital force; there is merely a gravitational force, which is acting as the centripital force.

now, there is a larger "centripital force" at the equator because e earth's rotation imparts acceleration opposite to gravitational acceleration; consequently, the gravitational force is felt to be smaller, and the normal force is felt to be smaller. at the north pole, the effect of rotation is minimal since the tangential speed of rotation is minimal.

 

[DrknoSDN]

I thought a bigger centripetal force is associated with a bigger normal force? Can someone clarify this?

This would be true if we were on the inner side of a hollow earth. It also applies to roller-coasters and embankments etc.

 

[justadream]

Here's the exact question:
"The variation of g in Table 1 is most likely due to"
Answer: Differing Centrifugal Forces at the Locations

@tdod
Can you explain "there is a larger "centripital force" at the equator because e earth's rotation imparts acceleration opposite to gravitational acceleration" further?

How is Earth's rotation imparting an acceleration opposite (do you mean like "going in the opposite direction"?) to gravity?