# Air Track Help

1. May 21, 2013

### physicsguru97

1. The problem statement, all variables and given/known data
Hello I've been doing this experiment which is about momentum and kinetic energy. I'm using an air track and using two carts one 3/4 of the way down with 50g weights I will add to it each time I test it this will be the variable i will be changing the cart will stay stationary. I will launch another cart with a constant velocity each time and it will hit the cart. My hypothesis is that when you increase the weight of the stationary object the distance of the cart moving will be further than the stationary cart. I also have to use all laws i could get out of this experiment

2. Relevant equations
i think i can talk about the conservation of momentum and energy i am really unsure what else i can talk about and i have to show working out using formulas

3. The attempt at a solution
I believe i can calculate the acceleration using a stop watch but could anyone else suggest any more equations and how to work it out im quite unsure

2. May 21, 2013

### vk6kro

Air tracks sometimes have a spark system so they leave marks on a paper tape every 1/25th of a second.

If yours has provision for this, you can do accurate tests.

Others have "ticker timers" which drag a paper strip through a stamping device which also leaves a mark. These are not as good as spark timers, but better than stop watches.

So it would be worth checking if any better timing is available.

3. May 22, 2013

### Staff: Mentor

I'm not sure about "distance" when the carts are moving on a low friction level track.

If you have editing software you maybe could use the frame rate of your webcam to determine the speeds of the carts. Regular cm marks are visible on the tracks?

4. May 24, 2013

### vk6kro

If the two carts have equal mass, the stationary cart will move away from the point of contact, while the moving cart will stop.

If the moving cart is lighter than the other, it will reverse direction and go back the way it came, but slower. The stationary cart will move in the opposite direction.

You can probably guess what will happen if the moving cart is the more massive.