Evaluation in Testing the Conservation of Momentum in a Linear Collision

To verify or test the law of conservation of linear momentum, the cart with two weights is pushed with a finger and moves at constant velocity. Half way through the air track is a stationary cart with no weights. Once the carts collide, they stick together and move at a slower constant velocity. At this collision, velocity decreases as mass increases, meeting at equilibrium in momentum before and after a collision. This air track has a near frictionless surface enabling the cart to move at constant velocity.

There are many possible explanations for the results of this experiment along with its limitations and faults. Firstly, the experiment carried some human errors such as when the cart is propelled by a finger; the force applied was not completely horizontal. In turn, the cart lifted off the track slightly and fell back down. This altered the results, as kinetic energy was lost due to the impact energy in a form of friction with the air track. Secondly, another human error includes misreading the increments on the equipments such as the ruler used to measure the distance between the points. Another limitation is the restriction to only one trial being conducted. This limitation made the experiment vulnerable to many undetected random errors. The results did not justify the law of conservation of linear momentum as the experiment was not performed in an isolated system, one in which external forces are absent. The carts could have been affected by air resistance and other environmental factors, leading to the non-equivalent results in the sum of momenta before and after the collision.

This experiment was conducted with many flaws, which gave me an opportunity to see errors that can be learned from to apply to future experiments in acquiring the knowledge from my experiences. To improve accuracy in results such as this case, the lab must comply with the law of conservation of linear momentum’s restriction. This experiment was to determine the extent to which momentum is conserved in a simple linear collision. Mathematically the total momentum before and after a collision should be equal if the experiment is in an isolated system. Here this experiment, the air track was open to many environmental factors that altered the results. In future experiments, to verify or justify the hypothesis, the lab must comply with the law’s conditions. Another improvement is to apply only a horizontal force so the cart will not experience much friction with the air track. Also, conducting more experiment should eliminate the majority of the random errors in accumulating an average from the results. In all, this experiment did exemplify that even in an open system, most of the momentum is conserved in this simple linear collision.