Science Competition Help - Potential Energy Cart

[BBscience]

For a high school physics competition I need to build a cart that is powered by a 1kg hook weight that will be dropped from 1m above the ground. This is a distance competition. The course will be flat. There is no limit to the size of the cart but it needs to fit in a 6ft wide course. The organizers will give me the weight and I can attatch it anyway I want as long as it fits the above decription. Also, no vaults or ramps are allowed.

Any help you can give me will be greatly appreciated.

[timo]

I'd try a rope (on which the weight hangs) and gears.

[swansont]

Other copies of this have been removed. No need to post this in more than one section

[Edtharan]

There are two ways you can go about this.

 

1) Inertia:

 

Make the cart travel fast and have a large mass so that the falling hook weight accelerates the cart fast and then when the hook weight reaches the ground the cart is released and allowed to run freely until friction slows it to a stop.

 

However, if the cart is too heavy, then the hook weight won't fall and friction will take most of your energy away.

 

Low friction bearing, wheels and running surface would be needed for this to be successful.

 

2) Mechanical Advantage:

 

The idea here is to use mechanical advantage to somehow increase the distance the cart moves for a given distance the weight falls. Using pulleys to give this mechanical advantage would be the easiest way.

 

The problem here is that you will only have a set distance you can travel as dictated by the ratio of the pulleys and that there will be a lot of friction in the pulleys which you will have to deal with. A lighter cart would be an advantage here as it would cause less strain on the pulleys and so less friction (and easier to start moving - overcoming the static friction of the system).

 

Low friction pulleys and a low weight cart are needed for this.

 

There might be a third option.

 

3) Hybrid:

 

You might be able to make a hybrid system where you use mechanical advantage to turn the energy of the falling pulley into a higher kinetic speed.