Acceleration through a non-uniform curve

In summary, the conversation discusses the design of a roller coaster for a project and the need to find the lateral and up/down g forces acting on the rider. The speaker has created a function for the roller coaster but is struggling with finding the acceleration components, as the velocity depends on height rather than time due to conservation of energy. They have also looked at equations related to acceleration and position. The conversation then touches on the concept of the brachistochrone curve, which is the minimum transit time curve for a given start and finish point and is a cycloid. The story of Isaac Newton solving the problem in one day is also mentioned, and the hope for a brachistochrone roller coaster in the future is expressed.
  • #1
xoon
1
0
So we are designing a roller coaster for a project, the roller coaster starts at 100m above ground and it has to go through all of these elements. for the whole ride, i need to find the lateral and the up/down g forces that are acting on the rider.

for the roller coaster itself, i have made a function for the roller coaster but i do not know how to get the acceleration components.

what i have so far is that v=ds/dt. but the problem is that my velocity does not depend on time, it depends on height because of conservation of energy. my velocity right now is.. v=Sqrt(2*g*(ho-h)). i do not know where to go from here, because it does not depend on time. i need acceleration in terms of position.

some other equations I've looked at are dv/ds*v=a(s) --> v*dv=a(s)*ds

i've been staring at this for about a day now and the project is due monday. please help..
 
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  • #2
Also look at Isaac Newton's brachistochrone problem and solution. See

http://mathworld.wolfram.com/BrachistochroneProblem.html

The brachistochrone curve is the minimum transit time curve from start to finish, and is a cycloid. The cycloid initially accelerates very fast, the curve dips below the finish line, and then the acceleration lessens to zero and decelerates as the finish line is approached. See Mathematica simulation in

http://curvebank.calstatela.edu/brach/brach.htm

The story goes that someone proposed the problem to Newton, and he solved it in one day, having "invented" calculus of variations to do it.

I am hoping that someone, sometime, builds a brachistochrone roller coaster.

Bob S
 
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  • #3


Acceleration through a non-uniform curve can be a complex concept to understand, especially when designing a roller coaster. The first step in finding the lateral and up/down g-forces is to understand the acceleration components. As you have mentioned, the velocity of the roller coaster depends on the height, not time, due to conservation of energy. This means that the roller coaster's kinetic energy is constantly changing, but the total energy (potential + kinetic) remains constant.

To find the acceleration components, we can use the equation a = dv/dt, where a is the acceleration, v is the velocity, and t is time. However, in this case, we need to use a different equation since the velocity depends on the position, not time. We can use the chain rule to rewrite the equation as a = dv/ds * ds/dt. Since ds/dt is the velocity, we can substitute it with the equation you have already found, v = √(2g(ho-h)), where ho is the initial height and h is the current height.

This gives us a = dv/ds * √(2g(ho-h)). We can simplify this further by using the fact that dv/ds = a(s), where a(s) is the acceleration as a function of position. This gives us the final equation, a = a(s) * √(2g(ho-h)). Now, we can find the lateral and up/down g-forces by using the equation F = ma, where F is the force, m is the mass of the rider, and a is the acceleration we just found.

I understand that this concept can be overwhelming, especially with a looming deadline. I would suggest seeking help from a teacher or a tutor to better understand the concept and apply it to your project. You can also try breaking down the roller coaster into smaller sections and finding the acceleration for each section separately, then combining them to find the overall acceleration. Best of luck with your project!
 

1. What is meant by "non-uniform curve" in the context of acceleration?

In physics, a non-uniform curve refers to a curve or path that does not have a constant or uniform acceleration. This means that the rate of change of velocity is not constant along the path, and the object is experiencing a changing acceleration.

2. How is acceleration through a non-uniform curve different from acceleration through a straight line?

The main difference is that in a non-uniform curve, the direction of acceleration is constantly changing, while in a straight line, the direction remains constant. This is due to the changing direction of the object's velocity in a non-uniform curve.

3. What factors can affect the acceleration through a non-uniform curve?

There are several factors that can affect the acceleration through a non-uniform curve, including the object's mass, the shape of the curve, and any external forces acting on the object, such as friction or gravity.

4. Can an object's acceleration through a non-uniform curve ever be zero?

Yes, an object's acceleration can be zero at any point along a non-uniform curve. This would occur when the object is moving at a constant velocity and there is no change in its acceleration. However, the direction of the object's velocity may still be changing.

5. How is acceleration through a non-uniform curve calculated and measured?

Acceleration through a non-uniform curve can be calculated using the equation a = (vf - vi) / t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time. This can be measured using tools such as accelerometers or by analyzing the change in an object's velocity over time.

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