What Is the Normal Force on a Rollercoaster Car at the Top of a Hill?

Click For Summary

Homework Help Overview

The problem involves a roller-coaster car with a specified mass, moving over the top of a circular hill. The focus is on determining the normal force exerted on the car by the track at two different speeds while considering the forces acting on the car.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the application of equations related to circular motion and forces, noting discrepancies in calculated normal force values for different speeds. There is a focus on checking the signs of the forces involved and questioning the assumptions about the forces acting on the roller coaster.

Discussion Status

Some participants have provided guidance on checking the sign of the force and considering the implications of the forces required to maintain circular motion. Multiple interpretations of the problem are being explored, particularly regarding the role of the normal force and gravitational force at the top of the hill.

Contextual Notes

Participants are working with specific values for mass, radius, and speeds, and there is an emphasis on the correct application of physics principles in a homework context. The problem is sourced from Wiley Plus, indicating potential constraints on the approach or format expected in the responses.

arrax
Messages
4
Reaction score
0

Homework Statement


A roller-coaster car has a mass of 1150 kg when fully loaded with passengers. As the car passes over the top of a circular hill of radius 16 m, its speed is not changing. (a) At the top of the hill, what is the normal force (using the negative sign for the downward direction) FN on the car from the track if the car's speed is v = 8.5 m/s? (b) What is FN if v = 20 m/s?

m=1150kg
R=16m
v= 8.5 or 20


Homework Equations



a=v^2/R
F=m*[(v^2)/R]
-FN-mg=m[(-v^2)/R]


The Attempt at a Solution



Using the above equation I got b) correct with -17468.5 N. However, using the same equation with a) I get -6088.53 and it's incorrect. I don't know what I'm doing wrong.

Also, this is from Wiley Plus.
 
Physics news on Phys.org


arrax said:

The Attempt at a Solution



Using the above equation I got b) correct with -17468.5 N. However, using the same equation with a) I get -6088.53 and it's incorrect. I don't know what I'm doing wrong.

Also, this is from Wiley Plus.

Check the sign of the force.

ehild
 


aside from a possible wrong sign, did you get a different number?
 


Think: can the track pull the roller coaster? What happens if upward force is needed to keep it on circular path?

ehild
 

Similar threads

Normal Force on Car at Top of Rounded Hill
  • · Replies 2 ·
Replies
2
Views
2K
Super Fun Rollercoaster Problem
  • · Replies 3 ·
Replies
3
Views
2K
Worksheet Problem about Power (average power of a car accelerating up a hill)
  • · Replies 2 ·
Replies
2
Views
2K
Question About centrifugal force of a moving car
  • · Replies 5 ·
Replies
5
Views
2K
Solving for Speed on a Roller Coaster's Top of Hill
  • · Replies 6 ·
Replies
6
Views
19K
Why Does the Scale Read Higher at the Top of a Rollercoaster Loop?
  • · Replies 1 ·
Replies
1
Views
4K
Circular Motion. Roller-coaster mass of car and max speed
  • · Replies 7 ·
Replies
7
Views
6K
Will the car make it to the top of the hill?
  • · Replies 5 ·
Replies
5
Views
2K
Force exerted on a seat on rollercoaster
  • · Replies 2 ·
Replies
2
Views
5K
Calculating Rollercoaster Energy and Designing for Conservation
  • · Replies 5 ·
Replies
5
Views
3K