Momentum, Impulse and Collisions

Purpose: The purpose of the lab was to see whether the impulse - momentum theorem worked during different types of collisions shown by two carts and a piece of clay.

Procedure: We had three different types of collisions. Two elastic and one inelastic.

 The picture below depicts the elastic collisions. One cart was held in place while the other one was moving. Different weights were added so that we could see whether momentum was conserved even if the mass increased.

The picture below shows the inelastic collision where the moving cart will get stuck to a piece of clay and from there we would use momentum to see what would happen.

We would use the force sensor to get a force vs time graph and take the integral of the area under the curve and as a result that would give us impulse which would then lead us to get the conservation of momentum. We also had some hand calculations to see how far off we were from the actual answer. This is why we set up a motion sensor at the end of the track so we could calculate the velocity of the cart.

Data: The data we had gathered was all input into logger pro. From the motion sensor we acquired the velocity of the car which we used to get our calculations. The force vs time was used to calculate the actual conservation of momentum portion.

Below is the set up the professor wanted to use in order to get data for the lab and set up our graphs.

The graph below shows the result of the second collision. The result of the impulse was -0.2723 Ns when the mass was increased. The red portion represents whatever the motion detector acquired while the blue was the force sensor.

The graph below shows the result of the second collision. The impulse was -0.6706 Ns and this was when the cart was just by itself.

The last graph was that of an inelastic collision. The value of the impulse was -0.2351 Ns.

Calculations: The only calculations we had to come up with were the ones for the actual impulse. All of the values are listed below. We did mv(final) - mv(initial) in order to get the impulse. We then compared that to the impulse we had gotten from the one gotten from the lab. 

Summary: Overall, the lab was successful because the values gotten from the calculations were not far off from the actual values gotten from the lab. Some factors were not taken into consideration tough like friction, air resistance and the strength of the actual push the cart gave. Nevertheless, the lab gave accurate results and proved that the momentum-impulse theorem is accurate.