Lab Partners 10/19/18 Kathleen Boyce CC Larrazabal
Experiment #1
Key Question
What is the effect of changing the Net Force of a system on the acceleration of the system?
Variables
Independent Variable - Net Force of the system (Newtons)
Dependent Variable - Acceleration of the Cart (m/s/s)
Controls - Cart used, surface traveled across, motion sensor, hanger used, and the total mass of the system (we took mass from the cart and added it to the hanger, changing the net force acting on the system while keeping the total mass a constant)
Dependent Variable - Acceleration of the Cart (m/s/s)
Controls - Cart used, surface traveled across, motion sensor, hanger used, and the total mass of the system (we took mass from the cart and added it to the hanger, changing the net force acting on the system while keeping the total mass a constant)
Procedure
- We started with 20 grams of weight on the hanger and recorded the Net force of it
- We then recorded the acceleration of the cart (with weight being pulled by the force of the hanger
- After we recorded the acceleration, we changed the net force of the system by taking weight from the cart and adding it to the hanger
- Our weight ranged from 20-150 grams (or 0.383- 1.60 Newtons)
Net Force vs. Acceleration Graph
This graph shows a Linear relationship between Acceleration and Net force. The slope of the graph is 1.346 (m/s^2)/N and the y intercept is -0.3389 m/s^2. In actuality the Acceleration should be 0 when the Net Force is 0 because a Net Force of 0 Newtons would equate to an acceleration of 0 m/s/s.
Equation: Acceleration (m/s/s) = 1.346 ((m/s^2)/N) - 0.3389 N
Equation: Acceleration (m/s/s) = 1.346 ((m/s^2)/N) - 0.3389 N
Experiment #2
Key Question
What is the effect of changing the Mass of a system on the acceleration of the system?
Variables
Independent Variable - Mass of the System (Grams)
Dependent Variable - Acceleration of the Cart (m/s/s)
Controls - Cart used, surface traveled across, motion sensor, hanger used, and the Net Force of the system (To keep the net force the same, we keep the mass on the hanger at a constant 50g, while changing the mass added to the cart)
Dependent Variable - Acceleration of the Cart (m/s/s)
Controls - Cart used, surface traveled across, motion sensor, hanger used, and the Net Force of the system (To keep the net force the same, we keep the mass on the hanger at a constant 50g, while changing the mass added to the cart)
Lab Setup: Same as Experiment #1
Procedure
Conclusion
This lab added another aspect to the previous lab we did with the buggy. My group choose the easiest method to conduct, but it wasn't the most accurate; our graph of both position vs. time and velocity vs. time showed irregularities at the beginning and the end, which most likely influenced our data. This can most likely be attributed to our group letting the cart go after the motion sensor started. This experiment added an incline to the path traveled by the cart. With this, the velocity of the cart wasn't constant anymore. The graph of position vs. time showed a concave up increasing quadratic relationship, meaning that there is an increasing position velocity and a constant positive acceleration.
Weaknesses, Limitations, and Uncertainties
The motion sensor had the same limitations in this experiment as it did with the buggy lab; The motion sensor can only record distance on one side of the x-axis (no negative numbers). While this wasn't that much of a problem with this experiment, this is a problem in many other situations that the motion sensor can be used it. When using the motion sensor with logger pro, it doesn't let you delete points, so if there is a slight error when conducting the experiment you would need to start over. With the motion sensor it is a lot more accurate than using a stopwatch, but not as accurate as a video analysis. Uncertainties include the aforementioned human error, and the equation of the graphs being skewed by the data points at the beginning and end.
Experimental Improvements
Because of the nature of the motion sensor experiment, there was not much that could be changed about the process to improve it (the weaknesses and limitations couldn't be helped). Other than the error that was caused by my group releasing the cart later than we started the motion sensor, the experiment couldn't be improved.