The effect of mass on roller coaster cars

In summary, the conversation discussed a science fair project testing the effect of changes in mass on the time it takes for a car to complete a roller coaster track. The results showed that the lighter car finished the track faster than the heavier car, contrary to what was initially expected. The group explored different explanations, including energy changes and friction, but ultimately concluded that the formula for energy changes does not account for time and the heavier car may have a slower start due to its greater mass. The conversation also touched on the concept of kinetic energy and its relationship with mass and velocity.
  • #1
agbuyer
2
0
For my science fair project, I am testing the effect of changes in mass on the time it takes a car to complete a roller coaster track. The track is made of hotwheels track and has an initial ramp, two turns and a loop. I used the same car both times (once without added weight and once with an additional 10 grams). After testing for many trials, I found that the lighter car finished the track faster than the heavier car.
This is the opposite of what I thought would happen. I thought that because the heavier car had greater potential energy, it would go faster. As I research this question, I start the think that the two cars should have finished at the same time regardless of mass.
What is going on?
 
Physics news on Phys.org
  • #2
Look at the formula for what happens in energy changes. Theoretically, mass should not make any difference.

[tex]mgh = \frac{1}{2}mv^2 + friction[/tex]

[tex]mgh = \frac{1}{2}mv^2 + umg cos(\theta)d[/tex]

factor out the mass

[tex]gh = \frac{1}{2}v^2 + ug cos(\theta)d[/tex]

Everything left is a constant. Gravity doesn't change, the height of the car doesn't change, u (actually mew) doesn't change, the angle doesn't change. Velocity should not change either.


My original post had an explanation for why lighter was better but it was wrong. I'll half to think about this for a while.
 
Last edited:
  • #3
With the increase in mass you also increase the normal force the track exerts on the car and thus increase the force of friction between the track and the car which is why the heavier car takes longer
 
  • #4
With the increase in mass you also increase the normal force the track exerts on the car and thus increase the force of friction between the track and the car which is why the heavier car takes longer

Although that is the logical explanation, the math disproves it.
 
Last edited:
  • #5
Thanks for the help. Please keep thinking about this problem.

The formula doesn't take time into account. The heavier car starts more slowly because it has a greater mass, more inertia. So over the beginning part of the track, the heavier car is slower. Maybe over time it evens out but with the length of my track it doesn't?
 
  • #6
Alright... a = f / m f = m * g
a = (m*g)/m = g. Add a cosinus or sinus and you'll have the exact amount. This all is thesame for each car though, it doesn't depend of it's weight. It has to be either friction or aerodynamics. And I am not into either of those. Strange problem!
 
  • #7

Kinetic Energy = 1/2mv^2...therefore, as the mass is increased, the velocity is decreased. Hence the cart would take longer to to complete the roller coaster track because it travels at a lower velocity.
 

1. How does the mass of a roller coaster car affect its speed?

The mass of a roller coaster car affects its speed by influencing the amount of kinetic energy the car has. The heavier the car, the more potential energy it has at the top of a hill, and the faster it will travel as it gains speed going down the hill. However, the mass alone does not determine the speed of a roller coaster as other factors such as gravity, friction, and air resistance also play a role.

2. How does the mass of a roller coaster car affect its acceleration?

The mass of a roller coaster car affects its acceleration by determining the amount of force needed to move the car. The heavier the car, the more force is required to accelerate it. This means that a heavier car will have a slower acceleration compared to a lighter car. This is why roller coasters with heavier cars often have steeper drops and more twists and turns to maintain a thrilling ride.

3. How does the mass of a roller coaster car affect its safety?

The mass of a roller coaster car can affect its safety in several ways. A heavier car may put more strain on the track and support structures, making them more prone to wear and tear. This can potentially lead to accidents if the car's mass is not properly accounted for in the design and maintenance of the roller coaster. Additionally, a heavier car may also put more stress on riders, causing discomfort or injury.

4. How does the mass of a roller coaster car affect its passenger capacity?

The mass of a roller coaster car can affect its passenger capacity by limiting the number of riders it can safely carry. Heavier cars may require more power and support to operate, which can limit the number of cars that can run on the track at one time. This can result in longer wait times for riders, especially during peak hours.

5. How does the mass of a roller coaster car affect the overall experience for riders?

The mass of a roller coaster car can significantly impact the overall experience for riders. A heavier car may provide a more intense and thrilling ride, as it will have more momentum and kinetic energy. On the other hand, a lighter car may provide a smoother and more comfortable ride. The mass of the car, along with other factors such as speed, track design, and special effects, all contribute to the overall experience for riders on a roller coaster.

Similar threads

  • Introductory Physics Homework Help
Replies
3
Views
6K
Replies
12
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
15
Views
5K
  • Introductory Physics Homework Help
Replies
10
Views
4K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
16
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
5K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
2K
Back
Top