Impact of weight distribution on the acceleration of cars

[GoldRemove9500]

Homework Statement

Hi, I am a IB student writing my physics IA. I am doing an experiment with pasco car on 2m long low friction track. I am testing with different amounts of weight in front, middle, and rear part of the car. I aim to analyse the time it takes for car to reach the end of the track.

Relevant Equations

The essay is quite long so I need sources to support my theory that mass distribution has impact on the acceleration of cars. Is there any sources/articles you can suggest or should I change my investigation.

I searched online but I couldn't find sources to support my investigation, the ones I found are either about formula cars or trucks. Links, sources and especially articles will be useful. thanks.

 

[FactChecker]

Homework Statement: Hi, I am a IB student writing my physics IA. I am doing an experiment with pasco car on 2m long low friction track. I am testing with different amounts of weight in front, middle, and rear part of the car.

Same total mass?

I aim to analyse the time it takes for car to reach the end of the track.
Relevant Equations: The essay is quite long so I need sources to support my theory that mass distribution has impact on the acceleration of cars.

Do your experimental results support your theory? If you are experimenting, it is important to not bias your results with a preconceived theory.

Is there any sources/articles you can suggest or should I change my investigation.

I searched online but I couldn't find sources to support my investigation, the ones I found are either about formula cars or trucks. Links, sources and especially articles will be useful. thanks.

First, you should realize that F=mA, so your theory is really about the effect of weight distribution on the acceleration force, F. That is traction and rolling resistance. So tire traction and rolling resistance are central.

 

[Baluncore]

The mass distribution will be important when considered in connection with front or rear wheel drive.

What causes the vehicle to accelerate?
Is it front or rear wheel drive?

 

[GoldRemove9500]

The mass distribution will be important when considered in connection with front or rear wheel drive.

What causes the vehicle to accelerate?
Is it front or rear wheel drive?

The vehicle has a spring built in. In the image you can see the button on the left side that launches the car when pressed. I am not sure if it is front or rear wheel drive.

and the track looks like this

 

[GoldRemove9500]

Same total mass?

Do your experimental results support your theory? If you are experimenting, it is important to not bias your results with a preconceived theory.


First, you should realize that F=mA, so your theory is really about the effect of weight distribution on the acceleration force, F. That is traction and rolling resistance. So tire traction and rolling resistance are central.

I tried 450g, 820g, 975g for rear and front of the car to compare if the acceleration time has higher difference in increased weight.

Yes there was difference between front and rear part weight placement.

Okay then I will search more about traction and rolling resistance. Are there any sources you suggest?

 

[berkeman]

I am not sure if it is front or rear wheel drive.

Do you think this funny car could accelerate as quickly if it were front wheel drive?

https://www.nhra.com/news/2021/heri...nny-cars-headed-50th-firebird-ignitor-may-1-2

 

[Lnewqban]

I tried 450g, 820g, 975g for rear and front of the car to compare if the acceleration time has higher difference in increased weight.

Yes there was difference between front and rear part weight placement.

Okay then I will search more about traction and rolling resistance. Are there any sources you suggest?

This car does not have any driving wheels.
It is pushed forward by a built-in plunge.
I see no reason for obtaining different results due to weight distribution.

It is important that you select the same position of the plunge for each try, as well as that you measure the location, speed, etc. of the same point on the car.

I also see the manipulation of the plunge trigger button as a potential source of errors in the measurements.

Please, see:
https://www.pasco.com/products/lab-apparatus/mechanics/carts-and-tracks/me-6950

 

[hutchphd]

The most important final result of anyexperiment is "are my results significant". This does not mean that they will change physics (or not). It means "do I know my conclusion is real (meanuing reliable and not a fluke). That is the sine qua non of any experiment. For inatance you must quantify how various is the button push by repeatedly changing only that and taking data. Nobody cares about weights in model cars but care greatly that your experiment was well designed. This is usually the difficult part of any experiment and typically demands controlled repetitions and statistical design thereof..

 

[FactChecker]

IMO, looking for references is not the most important thing. This is a learning exercise for a class. One important thing to learn is to look very hard for things that might invalidate your experiment. What if there is a difference when the weight is heavier on a bad axle? Is there some way to rule things like that out?

PS. I say this because I agree with @Lnewqban that I don't see why the weight distribution should matter in theory.