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Mack
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At the moment, I am reading an example problem regarding what was alluded to in the title. In this example problem, they say, "Based on experiences you may have had on a ferris wheel or driving over small hills on a roadway, you would expect to feel lighter at the top of the path. Similarly, you would expect to feel heavier at the bottom of the path."

Quite honestly, this is not what my intuition speaks to me: I would expect to have a greater normal force at the top of a hill, due to my inertia wanting to keep me at the bottom of the hill, thus the seat pushing up into me; for driving down a hill, I would expect my normal force to be less, because my inertia wants to keep me on top of the hill, therefore, the seat travels from beneath me.

I trust that the book is correct, but I would really like to know why I am wrong.

Thank you!

Edit:

Also, in the example problem, they analyze the forces acting on a person in a ferris wheel while at the bottom and top of it. For the bottom, $\Sigma F = N_{bottom} - mg = m \frac{v^2}{r}$; for the top, $\Sigma F = mg - N_{top} = m\frac{v^2}{r}$. Why does the normal force and weight change signs in each case?

At the moment, I am reading an example problem regarding what was alluded to in the title. In this example problem, they say, "Based on experiences you may have had on a ferris wheel or driving over small hills on a roadway, you would expect to feel lighter at the top of the path. Similarly, you would expect to feel heavier at the bottom of the path."

Quite honestly, this is not what my intuition speaks to me: I would expect to have a greater normal force at the top of a hill, due to my inertia wanting to keep me at the bottom of the hill, thus the seat pushing up into me; for driving down a hill, I would expect my normal force to be less, because my inertia wants to keep me on top of the hill, therefore, the seat travels from beneath me.

I trust that the book is correct, but I would really like to know why I am wrong.

Thank you!

At the moment, I am reading an example problem regarding what was alluded to in the title. In this example problem, they say, "Based on experiences you may have had on a ferris wheel or driving over small hills on a roadway, you would expect to feel lighter at the top of the path. Similarly, you would expect to feel heavier at the bottom of the path."

Quite honestly, this is not what my intuition speaks to me: I would expect to have a greater normal force at the top of a hill, due to my inertia wanting to keep me at the bottom of the hill, thus the seat pushing up into me; for driving down a hill, I would expect my normal force to be less, because my inertia wants to keep me on top of the hill, therefore, the seat travels from beneath me.

I trust that the book is correct, but I would really like to know why I am wrong.

Thank you!

Edit:

Also, in the example problem, they analyze the forces acting on a person in a ferris wheel while at the bottom and top of it. For the bottom, $\Sigma F = N_{bottom} - mg = m \frac{v^2}{r}$; for the top, $\Sigma F = mg - N_{top} = m\frac{v^2}{r}$. Why does the normal force and weight change signs in each case?

Source Link
Mack
  • 453
  • 5
  • 19
  • 29

Normal Forces and Ferris Wheels

At the moment, I am reading an example problem regarding what was alluded to in the title. In this example problem, they say, "Based on experiences you may have had on a ferris wheel or driving over small hills on a roadway, you would expect to feel lighter at the top of the path. Similarly, you would expect to feel heavier at the bottom of the path."

Quite honestly, this is not what my intuition speaks to me: I would expect to have a greater normal force at the top of a hill, due to my inertia wanting to keep me at the bottom of the hill, thus the seat pushing up into me; for driving down a hill, I would expect my normal force to be less, because my inertia wants to keep me on top of the hill, therefore, the seat travels from beneath me.

I trust that the book is correct, but I would really like to know why I am wrong.

Thank you!