# Homework Help: DeLorean Acceleration in Back to the Future III

1. Nov 19, 2008

### Smeagol3

For a semester project in my physics class, I am determining whether this is physically possible.

In Back to the Future III, Marty and Doc use the train to push the DeLorean, and must accelerate to 88 mph before they fly off the cliff.

I'm trying to figure out whether it's realistic for a train to accelerate to 88 mph in that distance.

I know the starting velocity is 0 and the ending velocity is 88 mph. I need to figure out the mass of the train and the distance.

For the train I'm planning on finding a normal steam train weight for that time, and for distance, I plan to estimate it based on Doc's scale model.

Do you think this will be difficult to figure out, and do you have any advice?

Thanks,
Smeagol3

2. Nov 19, 2008

### Stovebolt

Sounds like a fun project.

My guess is that you will have a seemingly infinite number of variables, so I would advise you to factor out as many as you can unless you feel they are critical to your project. Things like aerodynamic drag and wheel-track friction will make the project more realistic in concept, but if you use rough estimates for these values you may actually make your answer less accurate. If you do ignore a factor, make sure you make a notation of it in any reports and give a reason for not using it.

You might find some old engineering guide books to be of value. I did a quick search and found a 1916 American Civil Engineer's Pocket Book on Google Books with some info on old locomotives http://books.google.com/books?id=1l...oi=book_result&resnum=10&ct=result#PPA203,M1"

Remember that the power output of a steam engine is going to be related to the pressure the boiler can reach. I think that will likely be the theoretical limiting factor for this project.

Good luck and have fun!

Last edited by a moderator: Apr 23, 2017