Ma (without weight) = .5005kg
Mb = .4882kg
After taking these measurements, we set up our experiment. We leaded one cart with the weight and pushed it until it hit another cart. Our motion sensors gave us numerical values for velocities before and after the crash, allowing us to graph the data and get an equation describing velocity before and after the crash.
Our setup looked as follows:
Our data that we collected from the motion sensor (with trials 1-7) and data when graphed looks as follows:
| Velocity of A Before | Velocity of both after | |
| 0.63 | 0.38 | |
| 0.69 | 0.43 | |
| 0.69 | 0.46 | |
| 0.62 | 0.39 | |
| 0.55 | 0.34 | |
| 0.7 | 0.46 | |
| 0.63 | 0.4 | |
The equation is: (velocity of both carts after crash) = (.7945)(velocity of cart A before crash)
This means that if the velocity of cart A before the crash was 1 m/s, then the velocity after the crash would be .7945 m/s. We can use this data, which is an average, to find the mass of the weight.
How we found the mass of the weight: Remember, Ma = the mass of the cart wight he object.We used the velocities from our equation (data above) before and after the crash in order to be as precise as possible. We plugged all of the values into our momentum conservation equation and then solved for the mass of cart A (wight he unknown object on top).
Then, to solve for just the mass of the object, we did as follows: (we weighed the mass of cart A which is how we got that value)
Conclusion:
So, we predicted that our mass would be .87kg. We then weighed the object to see how close we were. The object actually weighed 3.4kg, a HUGE difference. I blame this on the super small number of trials with a very small variation in velocities. This data was not enough to give us accurate data, messing up our prediction. If we would have taken more data points with more variation, we probably would have gotten much closer.
% error (I apologize for the sideways picture, it won't turn):
