Lab Partners: Max McCandles and Vincent Mele
Date of Completion: 12-26-14
Date of Completion: 12-26-14
Purpose
The purpose of this lab is to determine that impulse really is equal to the change in momentum of an object.
Theory
Impulse is defined as the change in momentum of an object. The change in momentum of an object can be found by multiplying the mass of an object by the velocity of the same object. When either the mass or the velocity of the object is changing, either variables must then be represented by the change in their respective velocity or mass. The impulse of an object can be defined as the area under the curve of the graph of the force of the object over time. The impulse, as found via the area under the curve method, should be equal to the calculated value of the change in momentum that is found by multiplying the mass times the velocity.
Experimental Technique
- Set up Data Studio as well as the experimental apparatus; note that the number of hertz on the force sensor must be set very high for precise measurements
- Zero the force meter
- Attach spring to force meter
- Set data studio to record data
- Drop cart from randomly selected height, assuring that the force of it will not exceed 50 N, as the force sensor is not built to read past that
- Use data studio to measure the change in velocity over the time that the collision of the cart with the spring occurred
- Use data studio to measure the area under the curve of the force vs. time graph
- Calculate the change in momentum and compare this with the area found under the force curve
- Repeat steps 3-8, only switch out the spring on the force meter for either a different spring, a rubber stopper, or a magnet strip, and drop the cart from a different height
- Record data
Data and Analysis
Conclusion
Impulse can be defined as the change in momentum of an object. This experiment was intended to determine whether or not this definition is accurate. The change in momentum, in this case, can be defined as the mass of an object multiplied by the change in velocity of the object. Impulse can be defined as the area under the curve of the force vs. time graph of the object. When the area under said curve was found using data studio and compared to the calculated change in momentum, the results were inconclusive. Though the settings of the motion sensor and the force sensor were altered in the hopes of achieving more accurate results, the data recorded unfortunately showed little correlation between impulse and change in momentum overall. It is more likely that the collision occurred too fast for the instruments to record than it is likely that the theory, which has not been heavily argued against, is inaccurate and was just disproven by this experimental procedure. Some additional error may have occurred due to the angle of the drop and the friction in the cart and track.