physicsguru97 said:
Hey does anyone have any good suggestions for an experiment for both of these topics momentum and friction? Because I'm currently doing a physics investigated research task that's about if you go a KM over or mile over it is worse. so i need to do some investigating that links the two topics to a real life situation. i was think for friction about using some type of device car I'm not sure so someone suggest something to go at a constant velocity and make it stop at a distance like a car accident and change the surface of the flooring but i don't know what to use to make a toy car or something else to a constant velocity
One thought comes to mind. I'm not sure it fits exactly, but it could probably be modified to fit your criteria.
In "Tractor Pulling" racing, the sled pulled behind the high-performance tractors has a mechanism that gradually increases the friction of the sled with the dirt track as the tractor makes it farther down its run. That makes it harder and harder to pull, due to the increasing friction. To achieve a "full pull", the tractor has to have enough power being delivered to the dirt through its rear wheels in order to keep pulling the sled in its maximum friction configuration.
http://en.wikipedia.org/wiki/Tractor_pull
Now, you might be able to do an unpowered demonstration version of this, where you give a cart an initial push, and there is a sled mechanism in contact with the ground. You could contrast how far the cart & sled get when the sled is in the minimum friction position the whole time, versus in the maximum friction position the whole time, versus the variable friction configuration...
You could also put some cool photos in your lab report, showing the inspiration for your lab demonstration...
http://www.farmmachineryshow.org/images/TractorPullPhotos/pull1.jpg
http://www.clarksd.com/potato/images/kids%20pedal%20tractor%20pull%202006%201.jpg