Rollercoasters and Loops and Normal Forces

AI Thread Summary
To find the normal force at the top of a loop in a rollercoaster, the equation derived is FN = Fc - Fg, where Fc is the centripetal force and Fg is the gravitational force. The user initially calculated that the normal force is zero, indicating a minimum height scenario. However, further discussion clarified that a general equation is needed to express the normal force at any height using only the variables m, g, and r. The user seeks assistance in formulating this general equation. The goal is to accurately determine the normal force at the top of the loop for varying heights.
komarxian
Messages
37
Reaction score
0

Homework Statement


<I will attach a diagram below> In terms of m, g and r. FInd the normal force at the top of the loop.

Homework Equations


∑F = Fc = FN+Fg ∴ Fc=FN+Fg ∴FN = Fc - Fg ∴ N=mV2/r - mg

The Attempt at a Solution


Fc=mV2/r - mg and V2=ra and a=g ∴C=mrg/r ∴C = mg ∴mg-mg=N ∴ N=0 N. BUT after discussing with a guy in AP Physics C at my school, he said that this is solving for the minimum height. SO I think I need to solve for the general equation to solve for the normal force at the top of the loop at any height using the variables m, g, and r only (I'm pretty sure that's what my instructions meant). Could anyone help please? I will send an image of my work as well.
 
Physics news on Phys.org
ImageUploadedByPhysics Forums1454644340.451261.jpg
ImageUploadedByPhysics Forums1454644365.518475.jpg
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

[Grade 12 Physics] Gravitational/circular motion #2
Replies
5
Views
2K
[Grade 12 Physics] Circular/gravitational motion
Replies
21
Views
3K
Circular motion of a rollercoaster car on a loop-the-loop
Replies
14
Views
1K
Uniform Circular Motion: Tension Force at Top of Circle
Replies
4
Views
1K
Loop the Loop Problem Solution | N > 0, Energy Conservation Method
Replies
8
Views
3K
Find g, measured to be 9.78 at the equator, when Earth is still
Replies
17
Views
2K
Circular motion - ball in a loop
Replies
19
Views
4K
Would a marble need the same speed as a car at the bottom of a vertical loop?
Replies
7
Views
2K
Centripetal force problem involving a washing machine
Replies
5
Views
3K
Find tangential velocity given radius and the coefficient of friction
Replies
3
Views
3K

Hot Threads

Recent Insights

Back
Top