![]()
![]()
Coaster Dynamics
Coaster Lab
Lesson #7: Nonconservative Forces: Working for a Living
TOPICS: Conservation of Energy and Friction.
1. Starting with the default track configuration in
Coaster Dynamics, run the roller coaster ride and stop it after the car passes the bottom of the Lift Hill.Use the
Coaster Lab feature to determine the y coordinate and the speed (magnitude of the velocity) at each of the 11 Watchpoints in the Lift Hill. Calculate the total energy (kinetic + potential) at each of the 11 Watchpoints.
![]() |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|v| | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
y | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
E | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
2. Turn the track friction option OFF (found under the "Coaster Lab" => "Track Parameters" submenu). Repeat Part 1 with the friction now turned off.
![]() |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|v| | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
y | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
E | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
3. Calculate the total nonconservative work (friction plus air resistance) at each Watchpoint by subtracting the total energy values in Part 1 from those in Part 2. Also record the track pathlength at each Watchpoint.
![]() |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
Wnc | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
L | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
4. Calculate the total nonconservative work consumed in each increment between Watchpoints by subtracting the appropriate amounts of energy using the data in Part 3. Also calculate the length of each increment from the pathlength data in Part 3.
In the days before computers, simple friction models were used to estimate the final speed of a roller coaster versus the length of track. Using the equation for work, and assuming the simple friction model below,
Wf = (Ff)(
L)
Ff = (µ)(mg)
calculate the implied value for the friction coefficient, µ, for each increment between Watchpoints.
Calculate an average value for µ from your data.
![]() |
1-2 | 2-3 | 3-4 | 4-5 | 5-6 | 6-7 | 7-8 | 8-9 | 9-10 | 10-11 |
Wnc | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
µ | ![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
5. Design a new roller coaster track that will successfully reach the end with a final speed less than 5 m/s.
Calculate the total energy loss for your new track by subtracting the remaining energy at the end from the initial energy at the top of the Lift Hill.
6. Estimate the total energy loss of your track by calculating the work done by friction, using the the total track pathlength and the average friction coefficeint you calculated in Part 4.
How does this compare to your result in Part 5?
Copyright © 2001, Cyclone Software, Pleasanton, CA, USA. All rights reserved.