Physics Coursework Essay Example

Controlled

This variable will stay constant throughout the experiment. Several variables, including surface texture, distance between start and stop positions, length of the string, person timing, and person letting go of the trolley, will be kept constant.

This evidence will be recorded separately and when needed, recalled for calculations such as acceleration.

Prediction

After careful consideration, I have decided to use the change in force pulling the trolley as the variable. This represents the force exerted by the girl in pushing her parents' shopping trolley around the supermarket. Hence, I must calculate the acceleration based on the increase in force used to push/pull the trolley. My prediction is that as the force pulling the trolley increases, so too will its acceleration.

Scientific Information

This paragraph provides information on various forces besides the weights acting on the trolley. The primary force that opposes the trolley's motion is friction, which prevents it from going faster. Since the table remains unchanged in this experiment, friction is expected to remain constant and not have a significant impact. Another force acting on the trolley is gravity, pulling it downwards.

The factors that contribute to the resistance and speed of the trolley are discussed in this paragraph. The friction of the table increases the resistance to forward movement, while Earth's gravitational force remains constant. As long as the mass of the trolley stays consistent, its speed will not change in each run. Gravitational force is also considered when calculating acceleration. Additionally, the weight on the mass holder is another force involved, which is affected by acceleration due to gravity. As weights

descend, this acceleration increases and applies more Newtons on the string, ultimately increasing the trolley's speed.

Apparatus List

This section provides a list of all apparatus used in the experiment:

1. Trolley
2. Mass holder and multiple weights
3. String
4. Pulley attached to a table or surface
5. Two individuals: one releasing trolley and another recording time
6. Stopwatch
7. Start and stop point

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Diagram

Method

To prepare for this experiment, we initially attached a pulley to a table.

Initially, we fastened a string to the mass holder and the trolley. Subsequently, we identified the initial and final positions. The initial position was marked as the location where the front of the trolley was at when the top of the mass holder made contact with the pulley. To determine the final position, we noted where the front of the trolley was when the mass holder approached close to touching ground. After completing all necessary preparations, we were prepared to proceed with our experiment and simply had to document our findings.

Two individuals collaborated to carry out an experiment. One individual initiated the release of a trolley while the other individual measured the time it took. To ensure precision, they began timing when the trolley was at its starting point and released it simultaneously. They promptly stopped the stopwatch as soon as the trolley reached the stop line in order to acquire accurate findings. The goal was to determine the speed of the trolley by multiplying the distance it traveled with the time it took, while considering various weights that influenced its movement. The initial trial consisted of utilizing a 100g weight on the mass holder.

We performed three trials per individual using

eight distinct weights to determine the duration it took for the trolley to reach the finish line. One person was responsible for timing while the other released the trolley, and they regarded the collected data as their own. To facilitate additional computations, we recorded this data in a table.

Variety

Due to time constraints, we were constrained in terms of weight selection. However, we still required a range of weights. Consequently, we decided to increment the weight by 100 grams with each iteration.

The weights we obtained ranged from 1N to 8N, allowing us to efficiently conduct the experiment and obtain a diverse set of results.

Treatment of Results

To find the average result, we performed three trials for each weight of 100g. The mean was determined by adding up the three results and dividing by 3. These averages were then presented in a graph and table in the following section.

Interpretation

Statement: The final results of the experiment closely matched my initial predictions.

My hypothesis was confirmed as I observed that increasing the weight on the mass holder resulted in shorter intervals between start and stop, indicating increased acceleration for the mini trolley. The evidence clearly shows that as the mass increases, so does the acceleration of the trolley. Upon examining the results, a clear trend between force and acceleration became apparent.

As the force increased, the acceleration also increased. The results showed that the acceleration and force were directly proportional, with an even difference between them. The graph illustrates a positive correlation between the two variables. The graph would have shown a straight line if it weren't for Force 3N and Force 6N. Force 6N exhibited a steep rise and fall,

possibly due to an irregular result in the 6N measurement, which affected the overall average. In the end, the last two results were the same because they had the same average value.

The inaccuracy of the recorded data is attributed to the rapid acceleration. Two main errors were identified in this experiment. First, it became challenging to obtain precise readings of the time taken by the trolley to reach the stop mark as the acceleration increased due to the additional weights. This difficulty stemmed from relying solely on human reflexes. Second, friction acting on the trolley was a predicted source of error.

This becomes a problem as friction increases with acceleration, making it an unpredictable variable. There are several improvements that can be made for this experiment. The first and most important improvement is to use light or infrared gates that automatically record when the trolley passes by. These gates are highly accurate and compensate for inaccurate results due to human reaction times. Another improvement would be to use a smoother surface to reduce friction between the trolley and the surface, which would also improve result accuracy. A possible solution for this is using a trolley that hovers on a bed of air, greatly reducing friction.

The next improvement would be to increase the number of runs completed by each person, as this would result in a higher average. Currently, we were only able to complete 3 runs per person due to time limitations. Additionally, it would be beneficial to conduct the experiment using a different variable, specifically placing weights on top, to assess if this produces better or worse outcomes.